Fernando Forestieri proved an inspired half-time substitution for Watford as he scored two goals in 10 second-half minutes to sink Sheffield Wednesday 2-1 and send them into the top two.
The Hornets were trailing at half-time to Michail Antonio's 19th-minute opener when Gianfranco Zola introduced the on-loan striker at half-time, and it paid dividends within 20 minutes of the restart.
First he drove home Almen Abdi's corner in the 53rd minute and then he provided an emphatic finish just after the hour as Zola's men completed a turnaround.
With Hull losing at Crystal Palace it allowed them to move into the automatic promotion places, and they are now unbeaten in seven games and hitting their form just at the right time.
For Wednesday, it could have been a different story had they not wasted a host of first-half chances. After leading through Antonio's ninth of the season, which came courtesy of a Jonathan Bond howler in Watford's net, the Hornets keeper then produced a string of fine saves to keep the visitors' lead at one.
They were made to pay after the break and back-to-back defeats for the Owls mean they are only three points above the drop zone.
The Hornets are unbeaten at Vicarage Road since January 1 and they hit the ground running, spurning a couple of early chances to break the deadlock.
First Troy Deeney wasted an opportunity when he drove into the side-netting when 20-goal Matej Vydra was better placed for a pull back.
Vydra was then inches away from making it 21 for the season when he rattled the post from four yards after fine build-up play.
It looked like it was going to be one-way traffic, but Wednesday proved they were not just making the numbers up as they stole into a 19th-minute lead.
They were the recipients of a huge error from Watford keeper Bond as he could not control a wayward backpass by Marco Cassetti and Antonio nipped in to roll home.
That gave Jones' men confidence and they soon could have found themselves even further ahead.
Bond went some way to atoning for his error when produced two fine stops to first deny Llera's free-kick and then Jeremy Helan's drive, with Kieran Lee then hitting the rebound wide.
It was chances galore as both sides attacked, with Daniel Pudil testing Chris Kirkland and Joel Ekstrand blazing over for the hosts, while Bond again had to act smart to keep out Wickham and Danny Pugh efforts.
Boss Zola had seen enough and made two changes at half-time, bringing on Forestieri and Nathaniel Chalobah, and it paid dividends within eight minutes of the restart.
Abdi whipped in a corner, Cassetti flicked it on and Forestieri smashed into the roof of the net.
That allowed the Hornets to build up a full head of steam and Zola's decision to introduce Forestieri looked even better when he grabbed his second 10 minutes later.
Deeney sent in a deep cross, the striker controlled perfectly and drove home into the bottom corner.
Wednesday poured forward in search of a leveller and Bond had one final save to make as he kept out a Leroy Lita header at the death.