Tottenham moved into second place in the Premier League table as Kieran Trippier's first goal for the club sealed a dominant win over Watford.
The former Burnley full-back was in the right place to tap in substitute Dele Alli's fine low cross.
Spurs were always in control against a lacklustre Watford side, but were continually denied by their former goalkeeper Heurelho Gomes.
The Hornets failed to record a shot on target and fall to 10th in the table.
Spurs were always well on top, having 26 efforts on goal, but lacked the killer touch until Alli came off the bench to continue his superb season and tee up Trippier for the winner.
Alli was left out after feeling unwell during the 3-0 win at Norwich in midweek but quickly made the difference for Mauricio Pochettino's side once more.
You would have been forgiven for thinking on Saturday morning that the Premier League title was a two-horse race, such was the focus on leaders Leicester's trip to Manchester City.
But Spurs, with just three league defeats all season and seven wins from their last nine games, have crept under the radar to move into a great position to fight for their first title since 1961.
They have not finished second since 1963 but now have a squad who look capable of pushing Leicester and Manchester City all the way.
Leicester's stunning lunchtime win meant Spurs kicked off in the knowledge that a win would put them second overnight.
And their win against the Hornets would have been secured far earlier had Gomes - who had an eventful six-year stay at White Hart Lane - not made eight saves.
Spurs may be five points behind the Foxes but with Leicester facing Arsenal next weekend, while Spurs take on City, that could soon change.
Pochettino rotated his full-backs. leaving out Danny Rose and Kyle Walker, with Ben Davies and Trippier starting instead.
And both players fully justified their selection with superb attacking displays, providing the width in a patient, but attacking display.
In the first half Davies was twice denied by Gomes' reflex saves, and Trippier - who made 10 crosses from right-back - popped up in space to grab the winner when Alli's cross with the outside of his boot picked him out at the far post.
For Watford it was largely a day to forget. A damaging run of four straight defeats was arrested at the end of January but there was no sign of a side who had held Chelsea in midweek.
Manager Quique Sanchez Flores chose to split up his 20-goal strike partnership of Troy Deeney and Odion Ighalo, with Deeney tired after a gruelling run of games, but the change in system only served to leave Ighalo woefully isolated in the first half. Ighalo had the fewest touches (14) of any outfield player before Deeney came on at the break.
The captain's return made little difference though, as the Hornets ended the game without a single effort on target.
Tottenham boss Mauricio Pochettino, speaking to BBC Sport: "I feel very proud of the players.
"We need to be calm. We are in a very good position in the league but the philosophy from the beginning of the season has been to go step by step. We are a very young squad so it is important to keep going and take every game and competition and be ready to compete.
"We still need to be more clinical, we created a lot of chances but need to score more."