Slaven Bilic said West Ham should be proud of their surprise 2-0 London derby win over Arsenal but warned "it's only a start".
Bilic looked to be facing a baptism of fire in his first game as a Premier League manager, but the former Croatia coach masterminded a shock and long-awaited victory over Arsene Wenger's side.
West Ham had not beaten Arsenal for eight years before making the short trip to north London, but ended that barren spell courtesy of goals either side of half-time from Cheikhou Kouyate and Mauro Zarate.
Petr Cech, making his Premier League debut for Arsenal, flapped at a free-kick from the impressive Dimitri Payet to allow Kouyate to head home and the former Chelsea goalkeeper should have done better with Zarate's long-range strike.
Bilic faced criticism after fielding under-strength sides in the UEFA Europa League following West Ham's exit to Astra, but the former Besiktas boss was thrilled to hit the ground running in domestic action.
He said: "It's a great result for us, a great performance.
"To come here for the first game of the season you are hoping you are going to start well, because that is the best proof you are doing things right, then the players believe it is the right thing to do.
"To win a London derby against one of the biggest title contenders, against a team we have lost the last nine [Premier League] games against home or away, that sums up a really proud moment for the whole club and especially for the fans.
"It's only a start, but it's a great start."
Bilic again defended his team selection in the Europa League, with the Premier League being his priority.
"I took my decision considering everything," he explained.
"I wanted to go through, but I tried to see the bigger picture. I'm gutted that we didn't go through, but the main thing is this is the last season at Upton Park and we have to do well in the Premier League."
