West Bromwich Albion 2 Chelsea 3

The good news for Chelsea is that the defence of their title is up and running with a first victory of the season and that Pedro, on this evidence, will light up the Premier League with his presence. The bad news for José Mourinho to digest is that the champions continue to look vulnerable in at the back, with John Terry following his humiliating half-time substitution at Manchester City last Sunday with a straight red card here.

Terry's dismissal, early in the second half, changed the complexion of a breathless game that Chelsea seemed to have tied up when Cesar Azpilicueta, with his first Premier League goal, put the visitors 3-1 up just before half-time. Mark Clattenburg's decision appeared a little harsh at first glance, and Mourinho will no doubt rage against the referee's actions, but there was no escaping the fact that Terry was exposed or that he made contact with Salomón Rondón as Albion's record signing was bearing down on goal.

When James Morrison – who had missed a penalty when the match was goalless – scored his second of the afternoon shortly after Terry was sent off, it was tempting to wonder whether a stadium that has been a graveyard for Chelsea managers in recent years – Roberto di Matteo and Andre Villas-Boas both lost their jobs after defeats here – might provide another rude awakening.

Chelsea, however, held on for a crucial victory and one that highlighted what a shrewd piece of business it was to sign Pedro from under Manchester United’s noses. Pedro marked his debut with a goal to put Chelsea ahead, set up Diego Costa’s first of the season and created a host of other opportunities. He was, in short, a joy to watch.

It was a strange and absorbing match. By the time the interval came Chelsea were enjoying themselves and there was no hint of what was to come.

“Chelsea are back” chanted the travelling supporters after Costa, with his first goal of the season, doubled their lead on the half-hour mark.

It was a wonderful counterattacking goal as Chelsea broke from one end of the pitch to the other in the blink of an eye. Picking up possession from Terry’s header, Azpilicueta delivered a lovely diagonal pass that found Willian in the centre of the pitch. Willian carried the ball forward before releasing Pedro on the right and the winger drilled a low shot that Costa – whose run went totally unchecked – slid in from six yards.

Pedro had given Chelsea the lead 10 minutes earlier after a wonderful exchange with Eden Hazard on the edge of the area. Continuing his run, Pedro stroked a left-footed shot that took a slight deflection off Jonas Olsson before nestling in the corner of the net.

When Costa doubled Chelsea’s advantage it was difficult to see a way back for an Albion side set up to play on the break but Morrison gave them a flicker of hope in the 35th minute when he crashed home Rondon’s acrobatic cut-back following a James McClean cross.

How Morrison must have wished he could have been so clinical earlier in the game, when Thibaut Courtois saved the Albion poor midfielder’s penalty with a trailing leg after Nemanja Matic had brought down Callum McManaman.

It was a spot-kick that Saido Berahino would have taken ordinarily – he scored with one in the corresponding game last season – but Pulis had decided to leave the England Under-21 international out after judging that he was not in the right frame of mind to play on the back of Tottenham Hotspur’s attempts to prise him from The Hawthorns.

Chelsea were, however, soon back in control when Azpilicueta added their third. Cesc Fábregas started the move with a pitching wedge of a pass that Costa, taking the ball on this chest and holding off the challenge of Gareth McAuley, turned invitingly into the path of the Chelsea left-back.

With McManaman switching off, Azpilicueta darted inside and beat Myhill inside his near post.

At that point it seemed a matter of how many Chelsea wanted to score but Terry’s sending off proved to be a game-changer. Chris Brunt’s pass released Rondón over the top and Terry, chasing back, had his left hand on the Albion striker as he went to the floor just outside the Chelsea area.

Clattenburg reached for his pocket and pulled out a yellow card by mistake before brandishing a red.

Chelsea were down to 10 men and within five minutes Albion had a second goal. McManaman was involved again, delivering an inswinging cross from the left that Morrison got to ahead of Matic and met with a glancing header to send the ball arcing over Courtois.

It was game on at that point and McManaman came within inches of equalising when he jinked inside from the left, sitting Branislav Ivanovic on his backside in the process, and bent a low right-footed shot narrowly wide of Courtois's far post. At the other end, Costa, Radamel Falcao – set up by Pedro – and Hazard all squandered chances to put the game to bed.

(Guardian service)