Ireland striker James Collins came off the bench to score with his first touch as Luton beat arch rivals Watford at Kenilworth Road for the first time since 1993.
The Hatters, who were the better side for long periods, were awarded a penalty with 18 minutes to go, as Collins came off the bench to send keeper Daniel Bachmann the wrong way and net the only goal of the game.
The result dealt Watford’s automatic promotion hopes a blow, but Swansea and Brentford could only draw in the chase to win promotion behind Norwich.
Kiko Femenia was shown a red card late on to compound a poor day for Watford.
Ahead of kick-off a smoke bomb was thrown inside the ground while the players observed a minute’s silence in memory of the Duke of Edinburgh.
English Football League games were moved from their traditional 3pm kick-off slot due to Prince Philip’s funeral taking place at St George’s Chapel in Windsor Castle at the same time following his death last week at the age of 99.
As Luton and Watford players stood around the centre circle for a minute’s silence before the 12.30pm start, a smoke bomb was let off inside the ground close to the executive boxes and seating.
No players were near to the device when it exploded to reveal red smoke, but an image of it could be seen on a picture taken by Luton’s official Twitter account.
Due to the coronavirus pandemic, all EFL matches continue to be played behind closed doors, but it did not stop a slight disruption ahead of the derby fixture, with a steward forced to dispose of the smoke bomb before play was able to get under way.
Elsewhere in the Championship, a late fightback by Swansea at home to relegation-threatened Wycombe could not deny Norwich an instant return to the Premier League on Saturday afternoon.
Jamal Lowe and Liam Cullen struck in the final 10 minutes at the Liberty Stadium to earn the Swans a 2-2 draw, but with play-off rivals Brentford also drawing it meant the Canaries were able to secure automatic promotion from the Championship without kicking a ball.
Admiral Muskwe and Garath McCleary had put Wycombe two goals up to raise hopes Norwich would clinch a top-two finish ahead of their evening kick-off with Bournemouth and even though Steve Cooper’s side hit back, the draw leaves them third and 14 points off the leaders with four fixtures left in the regular season.
Victory for fourth-in-the-table Brentford at home to Millwall would have ensured the champagne stayed on ice at Carrow Road, but Lions goalkeeper Bartosz Bialkowski only had one save to make at Griffin Park in a stalemate between the London rivals.
Sheffield Wednesday were denied a vital three points at home to 10-man Bristol City in their battle to beat the drop after Tyreeq Bakinson levelled for the visitors in the 87th minute.
The Owls, who remain without manager Darren Moore as he recovers from coronavirus, went ahead with their first attack at Hillsborough through Julian Borner’s fourth-minute header.
It could have been 2-0 when Henri Lansbury was sent off for giving away a penalty midway through the first half, but Barry Bannan was denied from the spot and Bakinson hit a sucker punch when he fired in an equaliser late on.
Wednesday remain 23rd and seven points from safety while Yorkshire neighbours Huddersfield boosted their chances of beating relegation with a 2-0 win at Nottingham Forest.
Aaron Rowe broke the deadlock in stoppage time before the interval and Juninho Bacuna wrapped up the victory with a spectacular strike into the top corner midway through the second period.
Huddersfield are eight clear of the bottom three and only two points off Preston, who earned a point away to Stoke.
It finished goalless at the bet365 Stadium but the hosts finished the game with 10-men after Harry Souttar was sent off for a professional foul.
Another mid-table clash between Middlesbrough and QPR went the way of the London club by a 2-1 score despite playing with a numerical disadvantage for most of the second half.
Mark Warburton saw his team race out of the blocks at the Riverside with Rob Dickie and Lee Wallace netting inside 18 minutes.
Everton loanee Yannick Bolasie reduced the deficit before half-time and when goalkeeper Seny Dieng saw red after he clashed with Duncan Watmore outside his area, it looked a tall order for QPR to hang on but Joe Lumley impressed between the posts to help secure the victory.
