Watford boss Adrian Boothroyd warned Coca-Cola Championship promotion rivals Reading and Sheffield United that his side are gunning for them.
The Hornets destroyed the second-placed Blades 4-1 at Bramall Lane to serve resounding notice of their status as serious promotion contenders.
The remarkable success – Watford’s fifth straight Championship victory - lifted Boothroyd’s men to third spot on 58 points and above Leeds on goal difference.
A play-off spot looks an increasingly real prospect for the Hertfordshire club, but Boothroyd insists automatic promotion still remains within their grasp.
The Watford boss declared: “We’ll keep going until automatic promotion is mathematically impossible, but now it’s a little bit more possible.
“I don’t pay much attention to Leeds, Preston or Crystal Palace because we focus on what we’ve got to do.
“We don’t look behind us, we look above us and we try to push the teams that are above us. We’ve done that tonight and we’ll continue to do that.
“We’ve got a massive game now against Coventry on Saturday because the mark of a good team is to win well after you’ve just won well.
“As a result it’s the best of the season and as a performance that’s the best we’ve managed a game – mentally and emotionally – because it was a massive game.
“We countered well and could have scored more in the end.”
Goals from Chris Eagles, Hameur Bouazza and a brace from Marlon King handed Watford victory and placed a serious question mark over United’s automatic promotion ambitions.
The onus was firmly on the second-placed Blades to record victory and re-establish a 14-point advantage over closest rivals Leeds.
But the Hornets mercilessly tore up the script and thoroughly deserved to extend their unbeaten run at Bramall Lane to six matches.
Eagles, loan from Manchester United, netted with a delightful header after six minutes before he became embroiled in controversy 19 minutes later.
A tussle with David Unsworth led to the Blades left-back being shown a straight red card, while Eagles escaped with a booking before being replaced at the interval.
Two minutes after the restart, United defender Leigh Bromby gifted Marlon King a goal and although Paul Ifill hauled the Blades back into contention, King completed his brace and substitute Bouazza added a late fourth.
Blades boss Neil Warnock remained philosophical after the defeat but could not hide his disappointment with Unsworth, who he felt should have known better.
Warnock said: “You get these things in life. It’s one of those things, but we started off sluggish and gifted them a goal.
“We started getting back into it but then we get the sending off and it made it a hard task.
“David should know better; Eagles stamped on him and I can’t say he wasn’t provoked but David should know better.
“It was silly and something we need to eliminate because the same thing happened to Chris Morgan earlier in the season.”
Warnock was at pains to praise Watford but said: “They are a good side and full of enthusiasm, but quite a few things went their way, and they got away with certain things.”