Diego Costa scored twice for the hosts to cancel out goals from in-form duo Troy Deeney and Odion Ighalo, although Chelsea also missed a late chance to grab all three points when Oscar blazed a penalty over the crossbar.

Chelsea's Cesc Fabregas battles with Odion Ighalo of Watford on December 26, 2015 © Getty Images

It was the home side who made the brighter start to the match, dominating possession in the opening exchanges and fashioning the first chance of the game after just four minutes when Costa nodded over from close range.

Willian then saw a deflected free kick drop just past the far post before Watford began to gain a foothold in the game, and it was the Hornets who began to look more like scoring midway through the first half.

The best chances all fell to Ighalo, but he first snatched at a loose ball in the area when very well placed before planting a header wide having beaten Cesar Azpilicueta in the air from a corner.

Those misses were punished shortly after the half-hour mark when Chelsea registered the first goal in Hiddink's second era at the club, and it was Costa, booed by a pro-Jose Mourinho Stamford Bridge last weekend, who got the goal.

Diego Costa celebrates scoring Chelsea's first against Watford on December 26, 2015 © Getty Images

John Terry won the initial ball from Willian's corner, and it dropped to Costa on the edge of the six-yard box, allowing the Spaniard to lash home a first-time volley from close range.

Oscar squandered a good chance to double that advantage seven minutes later, while Watford came close themselves when Jose Jurado's deflected free kick flew narrowly past the post.

The Hornets would not have to wait much longer for their equaliser, however, as Nemanja Matic's bizarre handball gifted the visitors a penalty that Deeney duly dispatched to send the sides in level at the break.

Things got even better for Watford 10 minutes into the second half as, moments after Etienne Capoue had twice been denied, they completed the turnaround through Ighalo's 13th league goal of the season.

The Nigerian created a yard of room for himself to go for goal, and his deflected effort beat Thibaut Courtois as he became the first Watford player to ever score in five consecutive top-flight matches.

The lead lasted less than 10 minutes, however, as Costa doubled his personal tally to restore parity, latching on to Willian's incisive through-ball before slotting his finish past Heurelho Gomes.

Costa almost made it a hat-trick shortly afterwards when he attacked the front post to get on the end of Oscar's cross, but his bundled effort went narrowly wide.

The best chance for the hosts to regain the lead arrived with 10 minutes of the match remaining when Watford sub Valon Behrami clattered into the returning Eden Hazard inside the box, leaving Andre Marriner no option but to point to the spot for the second time in the match.

Unlike Deeney late in the first half, however, Oscar was unable to take advantage as he slipped when striking the ball, sending the spot kick well over the crossbar.

The visitors provided a late scare when both Ighalo and Deeney saw shots blocked in quick succession, but the match ended all square to leave Watford unbeaten in five and level on points with Manchester United.