After a week with plenty of changes in south London, it was perhaps inevitable a Crystal Palace old boy would have the decisive say. Aaron Wan-Bissaka lost his record of being the most expensive player Palace have sold to Michael Olise this summer, but he ensured instant hero status among his new supporters after coming off the bench to play a crucial role in West Ham’s opening goal by Tomas Soucek. Jarrod Bowen made sure of the victory five minutes later to seal Julen Lopetegui’s first win since succeeding David Moyes, thanks to a performance where they showed plenty of the grit so valued by his predecessor. For Oliver Glasner, who was hoping to make it a fifth successive Premier League victory at home for the first time in Palace’s history, this was worrying evidence that things may not be so easy for the Austrian after his instant impact last season. “We can’t dream of what we were doing three months ago, we have to be in the present,” he said. “It’s now up to us to keep calm and not be too disappointed – we will sleep really bad tonight but tomorrow the sun will rise.” An image of Glasner wearing 1920s-style overalls and inspecting plans for Selhurst Park featured on the front of the matchday programme to mark the 100th anniversary of Palace’s home ground. With the stalwarts Joachim Andersen and Jordan Ayew having moved on, he gave the new recruits Chadi Riad, Ismaïla Sarr and Daichi Kamada their home debuts, even if the arrival of Kamada off the bench midway through the second half was followed almost immediately by the game’s big moment. After finding themselves 4-0 down in 31 minutes during their last trip here 125 days ago, Lopetegui will have been pleased with the way West Ham applied themselves as Soucek headed wide from a corner before Mohammed Kudus shaved a post when Riad gave the ball away cheaply in his own half. Palace were missing the craft and guile of Olise after his move to Bayern Munich but at least they still have Eberechi Eze. The England midfielder was a constant thorn in Vladimir Coufal’s side and it required a brilliant save at his near post from Alphonse Areola to keep the scores level when Eze was played in by the impressive Adam Wharton. At the other end, Marc Guéhi – making his 100th Premier League appearance for Palace despite continued uncertainty about his future – was alert to block Michail Antonio’s follow-up after Bowen’s shot was saved. West Ham conceded 74 goals last season – their most in a Premier League campaign – but looked more assured here thanks to the calming presence of Max Kilman in their defence. There was nothing Areola could have done to stop Eze’s curling shot from a short corner routine but the West Ham goalkeeper was relieved to see it bounce off the crossbar. Lopetegui was spotted delivering some late words of wisdom to his players in the rain as they prepared to return for the second half and he said they were significantly better after the break. “We were fighting a lot but we had the feeling that we could be more aggressive,” he said. “I’m really pleased with how we adapted.” It was Palace who made the better start to the second half as Wharton – hard to miss with his socks rolled down and wearing pink-tinged boots – probed in midfield. Antonio’s run of scoring in four successive games against Palace came to an end when he was replaced by Niclas Füllkrug, with Wan-Bissaka also introduced. The defender’s first act against his former employers was to give the ball away, but his next contribution proved decisive when a surging run down the right allowed Soucek to slam home the loose ball in the area after Palace had failed to clear. There was some concern about a ballboy after an advertising hoarding fell on him while West Ham were celebrating their goal, with Soucek and Bowen lifting it off him before he was taken away for treatment. The home defence still seemed to be reeling from the shock of conceding when Kilman strode forward with purpose before picking out Bowen. The West Ham captain made no mistake to leave Palace pointless after two games.