Diego Costa controversially struck a late winner as Chelsea came from behind to beat Watford 2-1 on Saturday.

Having avoided being sent off for simulation in the second half at Vicarage Road the Spaniard took full advantage of referee Jon Moss' repreive, following up his winner against West Ham on Monday night with the decisive goal three minutes from time.

Etienne Capoue's stunning 55th-minute volley had given Watford a deserved lead until Chelsea responded through summer signing Michy Batshuayi, who scored his first Premier League goal 10 minutes from time.

The results sees Antonio Conte claim his second win from his two top-flight games, and sees the Blues move level with early leaders Manchester United. Watford, meanwhile, remain on one point from their two opening fixtures.

Walter Mazzarri stuck with the same Watford team that - despite Ben Watson's late dismissal - ground out a 1-1 draw at Southampton on the opening day. Conte, meanwhile, replaced Willian for Pedro in what was his only change from Chelsea's last outing.

Watford created the first opening as Miguel Britos' scything pass played Jose Holebas through on goal, but Thibaut Courtois was a match to the Greece international's strike on seven minutes.

The game ebbed and flowed in the opening exchanges as both sides enjoyed long spells of possession without threatening the opposition goal.

That was the case until 24 minutes, when Nodrin Amrabat bundled his way down the right flank, beat Cesar Azpilicueta and drilled a low ball into the Chelsea area.

Ighalo was poised to turn the ball home from six-yards, but Gary Cahill's intervention was enough to see the Nigeria international loop the ball over the target.

Watford continued to create the better chances as Adlene Guedioura blazed over the target on 32 minutes, seconds after John Terry had denied Ighalo was denied heading home with a perfectly-timed clearance.

Costa threatened in the closing stages of the half, forcing Heurelho Gomes to spilling a cross, but the Blues couldn't capitalise as the half ended level.

Watford resumed strongly and broke the deadlock within 10 minutes. A floated ball into the Chelsea area found Capoue at the far post, and the Frenchman controlled on his chest before rifling high past Courtois for his second goal in as many games.

Costa picked up a booking for gesticulating to the match officials in the aftermath of Watford's opener, and Chelsea looked lost for ideas when looking for a route back into the game.

Chelsea grew frustrated chasing the game, and Costa personified this by throwing himself to ground theatrically on 67 minutes in a bid to win a free-kick. Referee Moss opted not to dismiss the Spaniard for a second bookable offence.

But Conte's use of his substitutions proved to be decisive. First Victor Moses injected pace and energy into the tiring Chelsea attack, before the introduction of Batshuayi and Cesc Fabregas, overlooked for the second week running, added quality in the final third.

When an unsighted Gomes was unable to gather Eden Hazard's dipping drive, an eager Batshuayi was on hand to convert from close range for his first goal since his big-money summer move from Marseille.

Seven minutes later Fabregas' inch-perfect through ball released Costa, and he slotted the ball home under Gomes to complete the turnaround, and is could have been more secure had Batshuayi found the net instead of rattling the underside of the Watford goal in added time.

Player ratings

Watford: Gomes (5), Cathcart (6), Prodl (6), Britos (7), Amrabat (5), Behrami (5), Capoue (8), Guedioura (6), Holebas (6), Deeney (5), Ighalo (6).

Subs: Zuniga (4), Doucoure (4), Vydra (4).

Chelsea: Courtois (6), Ivanovic (7), Cahill (6), Terry (7), Azpilicueta (6), Kante (5), Pedro (6), Oscar (6), Matic (6), Hazard (7), Diego Costa (7).

Subs: Fabregas (4), Moses (5), Batshuayi (6).

Man of the Match: Etienne Capoue.

Teams

Watford Gomes, Cathcart, Prodi, Britos, Amrabat, Guedioura (Vydra 88), Behrami, Capoue (Doucoure 84), Holebas (Zuniga 90), Ighalo, Deeney (c)
Subs Not Used Pantilimon, Nyom, Anya, Hoban
Booked Deeney, Britos, Behrami, Holebas
Goals Capoue 55

Chelsea Courtois, Ivanovic , Cahill, Terry (c), Azpilicueta, Kante, Matic (Fabregas 78), Pedro (Moses 71), Oscar (Batshuayi 73), Hazard, Costa
Subs Not Used Begovic, Loftus-Cheek, Aina, Chalobah
Booked Cahill, Costa, Hazard
Goals Batshuayi 80, Costa 87

Attendance 20,772

Referee Jon Moss