Costa shot past Adrian for a dramatic late winner, after James Collins had equalised Eden Hazard’s penalty, but the striker was lucky to be on the pitch.
The Spaniard had been booked in the first half for dissent so was dicing with danger when he lunged in on Adrian as the keeper tried to dribble out of his goalmouth in the 67th minute. Costa caught Adrian on the knee with his studs, but referee Anthony Taylor did not even produce a second yellow, let alone the red that the foul deserved.
No wonder West Ham felt aggrieved, having lost out on victory in the corresponding game last season to a controversial late penalty from Chelsea. That time they had outplayed their west London rivals, although it has to be said that Chelsea were the better side this time. But they still look some way short of challenging Manchester City and United for the title They ended last season with a raucous game against Tottenham to kill off the north Londoners’ title hopes, and at times this game was almost as tempestuous, although it took a while to get going.
With the game failing to live up to its rich promise, there was as much entertainment to be had watching Conte and his Croatian counterpart Slaven Bilic prowling the technical area. Neither keeper been overworked in a first-half that started promisingly but turned scrappy quickly. Branislav Ivanovic forced one smart save from Adrian with a low shot inside his near post in the 12th minute, and he tipped over a free-kick from Willian in first-half stoppage time, but there was little of note in between.
N’Golo Kante was the only one of Conte’s new signings to start, in place of Cesc Fabregas, and it took only three minutes for the former Leiecester midfielder to make his mark – on the side of Andy Carroll’s calf. Kante was duly booked for the foul, and James Collins joined him in the referee’s notebook not long afterwards for clumsily taking out Costa.
It was that sort of game – plenty of passion but a lack of quality on the pitch. Both sides were guilty of unforced errors, giving the ball away with sloppy passes or being caught in possession. So it was fitting that the opening goal came from one such occasion, as Michail Antonio was caught out when he tried to run the ball out of defence shortly after half-time. Cesar Azpilicueta robbed the dithering Antonio, who then fouled the Chelsea left-back as he darted into the penalty area. Referee Anthony Taylor pointed to the spot, Hazard smashed the ball high into the roof of the net to open his account for the season.
Given that it took the Belgian wizard 29 league games last season to score his first goal in the league, Conte must have been pleased to see Chelsea’s playmaker get up and running so quickly.
Bilic, by contrast, was disheartened to see Andre Ayew, the club’s record signing, limp off with a thigh strain after barely half-an-hour. It left Andy Carroll to huff and puff on his own up front, to no great effect, and consequently Thibaut Courtois was hardly troubled in the Chelsea goal. Bilic had rested his own talisman, Dmitri Payet, considering the Frenchman to be short of match fitness following an extended pre-season break after his exertions at Euro 2016. Payet was inevitably involved when Collins equalised with a superb strike 13 minutes from the final whistle. The Welsh defender went up to get his head on a Payet corner, and as the ball rebounded back to him, he struck a sweet half-volley with his left foot from 15 yards, giving Courtois no chance.
Both managers went for broke in a bid to gain all three points. Conte sent on Pedro, who hit a late volley wide, and with time running out, Costa ran on to a flick from substitute Michy Batshuayi to smash a low shot past Adrian. It was game, set and match to Conte and Chelsea.
Courtois, Ivanovic, Cahill, Terry, Azpilicueta; Kante, Matic; Willian, Oscar, Hazard; Costa Chelsea subs: Pedro for Willian 79, Batshuyai for Hazard 85, Moses for Oscar 85
4-3-3 Adrian; Antonio, Reid, Collins, Masuaku; Kouyate, Nordveit, Noble; Ayew, Carroll, Valencia West Ham subs: Tore for Ayew 34, Byrom for Antonio 51, Payet for Nordtveit 66, Ref: Anthony Taylor