Despite falling behind to a Marko Arnautovic strike, his side hit back to win as Nacho Monreal and Danny Welbeck scored – with an Issa Diop own goal helping the hosts along to a 3-1 victory.
Bellerin set up two of the goals but struggled defensively at times as West Ham, whose pointless start to the campaign continues, arguably did enough to earn a draw.
“I wouldn’t describe it as relief,” Bellerin told Arsenal Media. “We’ve been working hard now for the last two months, so we knew it was just a question of time.
“We had two tough games to start after lots of changes at the club. We knew it was a question of time, a question of scoring the chances that we had.”
While Emery now has his first Premier League points, and rejected suggestions he had a row with Mesut Ozil before the game, Arsenal still made heavy weather of seeing off the Hammers and were lucky that the visitors lacked a cutting edge in front of goal.
“We still could have been even more efficient,” added Bellerin.
“But even though we started behind in the scores, we turned it around and I was very happy with the reaction of the team as well.
"We knew we were playing at home with our crowd, it was a tough team, they’ve had a very good summer window.
“They’ve signed loads of top players, so even though they were still getting used to each other as well, we knew it was going to be tough. I think the score doesn’t show how hard it was on the pitch.”
Manuel Pellegrini led an overhaul of the squad at West Ham having been appointed as the new boss at the London Stadium.
Eight new signings started at Arsenal – including former Gunner Jack Wilshere – but so far the former Manchester City manager has been unable to find a winning formula.
There were some strong individual performances as Felipe Anderson shone and former Arsenal goalkeeper Lukasz Fabianski made a number of key saves.
“The only sad thing from today’s game is that we lost,” Fabianski told whufc.com.
“Looking at it, it was a close game, and even in the last minutes of the game we had the chance to equalise.
“From what I saw today, even though we lost, I think we’re going in the right direction.
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