Watford rewrote the record books in south London this afternoon after producing one of their most memorable and clinical away performances for years to rise into the top six of the Championship with a magnificent 6-1 demolition of Millwall.

The Lions had come into the game defending a 21-match unbeaten home record dating back to November last year, but Kenny Jackett was forced to look on as the club where he made his name emphatically and ruthlessly scored the most goals in a game away from home since the infamous 7-4 victory at Burnley in 2003. Furhermore, the five-goal winning margin is believed to have equalled the Hornets’ biggest on their travels.

Incredibly, given what was to unfold, the opening few minutes suggested it was the Lions who were going to come flying out of the blocks, but, by the 14th minute, Watford had a firm stranglehold on the game thanks to captain John Eustace and Jordon Mutch’s first goal for the club.

It could have got even worse for the hosts before it got mildly better – with Steve Morison hitting the bar and Paul Robinson forcing Scott Loach into a good save – but, crucially, it was the Hornets who scored the next, with Marvin Sordell continuing his purple patch in first-half stoppage-time.

Although the game was effectively won, barring a complete collapse, there was to be no let up after the break from the visitors.

Adrian Mariappa headed in the fourth ten minutes after the restart and, although Liam Trotter pulled one back moments later, Danny Graham made it five before Martin Taylor headed home the sixth in the closing stages of a quite fantastic afternoon. And, but for beleaguered Lions keeper David Forde, Watford could easily have scored more because he made at least three top quality saves.

Despite winning 2-0 at Bristol City in mid-week, Malky Mackay opted to make one change, with the fit-again Lloyd Doyley coming in at right-back in place of Lee Hodson.

The Lions, who were two points and nine places ahead of the Hornets at kick-off, showed two alterations from the team that was held to a 0-0 draw at home by Reading on Tuesday night. Former Watford boss Jackett opted for Trotter in place of Tamika Mkandawire, while Neil Harris came in for Kevin Lisbie up front.

As well as the manager, the Watford old-boy connections continued in the home side’s line-up, with Darren Ward at the heart of the defence and Jack Smith and Theo Robinson among the substitutes.

The hosts were quickly out of the traps, with Doyley forced into an early frantic clearance, but it was their opponents who had the first attempt of the afternoon when Sordell’s scuffed attempt from the left angle of the area was gathered by Forde after three minutes.

The Hornets though, soon settled, winning the first corner of the game in the sixth minute and enjoying a reasonable spell of possession and another corner three minutes later. And, from that, the visitors got off to the ideal start.

Don Cowie drove in the ball from the right to the near post, Morison inadvertently flicked it on and presented Eustace with the simplest of finishes at the far post to make it 1-0 after netting his third of the campaign.

It could have got even better for Watford two minutes later when Sordell picked up the ball near the edge of the area, slid it through the defence and Mutch appeared to let it run for Graham, whose control let him down at the key moment.

But get better it did in the 14th minute, when the Hornets doubled their advantage.

Cowie and Graham were the instigators down the left, combining to good effect before the latter drove in a low cross which found Mutch in the six-yard box. The on-loan Birmingham City midfielder’s first attempt was blocked, but he made no mistake at the second time of asking, confidently beating Forde to make it 2-0 to score his first goal in yellow.

The badly rattled Lions won two corners in the 19th minute as they sought to establish a foothold in the contest, but it was their opponents who had the next attempt, with Will Buckley coming in off the right to find Cowie, who, in turn, fed Sordell, but his shot lacked power and Forde was able to save with ease.

Another opportunity came and went soon after when an Andrew Taylor throw from the left was held up by Graham, but Mutch went for power rather than placement from the left side of the area and sliced his attempt well wide.

But it took a fine save from Forde to prevent Sordell netting a third in the 25th minute after Buckley, again, cut through the Lions’ rearguard with ease before finding his in-form team-mate, whose powerful left-footed effort was superbly parried by the keeper.

It took a fine block from Andrew Taylor though, to prevent a Morrison shot from the right side of the area from troubling the Watford goal four minutes later after the former Stevenage striker got away from Martin Taylor with rather too much ease close to the touchline.

After Doyley had become the first player to be booked for a foul on Danny Schofield, Morison went closer still when a right-footed blast from an acute angle cannoned back off the face of the bar after Mariappa had failed to find touch with an attempted clearing header.

This was Millwall’s best spell of the match so far and Jimmy Abdou was the next to chance his arm with a deflected effort a yard or so wide of Scott Loach’s left-hand post. And, from the resulting set-piece, Lions captain Paul Robinson was left free in the area, but his header across goal was well kept out by the diving Loach.

The visitors weathered that mini-storm and gradually began to find their attacking feet again as the opening half drew to a close, only for proceedings to be interrupted by a moronic ‘fan’ running on to the pitch and, rather worryingly, advancing towards Doyley before he was grabbed by a steward.

Watford then had a reasonable penalty appeal rejected when, under pressure from Sordell, the ball bounced up and struck Ward on the hand. But the Hornets had no need to worry because in the second minute of injury time they netted their third.

Buckley was again involved with a right-footed shot that was blocked but it broke for Sordell, who appeared to mis-hit his left-footed follow-up, but it still totally wrong-footed Forde and the ball trickled past him into the bottom right-hand corner to put Watford in total command at the interval.

There was no surprise that Jackett opted to make a double change at the start of the second half, with ex-Hornet Theo Robinson replacing Harris up front, while James Henry made way for Chris Hackett.

The visitors started the second half as they had finished the first, on the front foot, before the card count was levelled up in the 51st minute when Scott Barron saw yellow for a foul on Buckley.

But if it was possible, a great afternoon got even better for Watford three minutes later when, after more great industry from Graham had won another corner, Mariappa got first run on his marker to meet Cowie’s set-piece from the right with a neat downward header that the static Lions defence and Forde could do nothing about as the visitors took a 4-0 lead.

With the benefit of hindsight, perhaps Mariappa’s decision to run back the length of the pitch to celebrate with Loach, nor Sordell’s subsequent booking for delaying the restart, was the best idea because Millwall pulled one back almost immediately.

In fairness, it was a well-worked goal, with Abdou swinging over a cross from the left and Trotter meeting it with a neat side-foot finish that gave Loach little hope of saving.

Schofield forced the Watford keeper into a smart stop with an angled drive, the England Under-21 stopper then made a more comfortable save from a Barron 25-yard free-kick, before the visitors made their first change on the hour-mark, with Stephen McGinn replacing Buckley.

Schofield had another long-range effort deflected behind in the 65th minute and then Sordell made way for Troy Deeney.

Only the woodwork prevented Watford from netting a fifth in the 69th minute when Cowie played a superb dummy that left him in plenty of space in the area, only for his left-footed strike to rebound down off the bar and Forde just got to the rebound ahead of Graham.

Watford completed their substitutions moments later when Hodson came on for Andrew Taylor, who was tiring, but it was Loach who was the next keeper to be called into action when he made a fine one-handed stop to keep out a Morison piledriver from the edge of the area.

The Lions forward then saw yellow for a foul on Cowie before Graham was put through one-on-one with Forde, but the Millwall keeper did well to keep out his well-struck effort.

But, after Mkandawire had come on for Abdou, Graham was not to be denied the goal his performance so richly deserved in the 77th minute.

Martin Taylor found the Hornets striker in space on the right edge of the area and the former Carlisle United man blasted a cross-shot beyond Forde to make it 5-1.

The chances kept coming, with Graham laying a lovely cushioned header into the path of McGinn, whose shot was blocked, before Forde made an excellent save at the foot of his near post to push behind a goal-bound drive from Deeney.

Mutch also forced the Millwall keeper to make yet another save before Graham could, and probably should have made it six in the closing stages, when he fired into the side netting after the visitors had broken three-on-one on the counter, with Mutch leading the charge.

It was then Eustace’s turn to turn on the style, with a majestic step-over that left an opponent trailing in his wake, before striking a left-footed effort that Forde was again equal to.

But the poor Millwall keeper – and it was hard not to feel some sympathy for him – was beaten for a sixth time as 90 minutes passed on the clock with a goal that was a virtual carbon copy of Mariappa’s at the start of the half.

Again Cowie took the set piece from the right, again the Hornets’ centre half got first run on his man, again the result was a downward header and, again, the ball finished up going in the same area of the net to round off a quite astonishing afternoon.

Millwall: Forde; Dunne, P Robinson, Ward, Barron; Henry (Hackett 46), Abdou (Mkandawire 76), Trotter, Schofield; Morison, Harris (T Robinson 46). Not used: Craig, Smith, Lisbie and Mildenhall.

Watford: Loach; Doyley, Mariappa, M Taylor, A Taylor (Hodson 70); Eustace; Buckley (McGinn 60), Mutch, Cowie; Sordell (Deeney 67), Graham. Not used: Walker, Gilmartin, Jenkins and Bennett.

Bookings: Doyley for a foul on Schofield after 31 mins; Barron for a foul on Buckley after 51 mins; Sordell for time-wasting after 54 mins; Morison for a foul on Cowie after 74 mins.

Referee: Neil Swarbrick.