Adrian hailed the efforts of his defence after West Ham United secured a memorable 2-1 victory over Manchester City on Saturday.
The Hammers withstood a strong City fightback after the break, once Morgan Amalfitano had given the home side a first half lead.
Diafra Sakho doubled the advantage in the closing stages, after the Hammers had thwarted the likes of Sergio Aguero, Edin Dzeko and Stevan Jovetic, and although David Silva pulled one back, West Ham held on.
"It was a very happy dressing room after the game," Adrian said. "It's a massive three points for us and the team played so well.
"Manchester City came on strongly in the second half but the team defended well and it's an unbelievable win.
"In the Premier League every game is difficult and they have Dzeko, Aguero and Jovetic - it's hard work for a goalkeeper!
"But we had a clean sheet in the first half, Silva scored a good goal in the second half but we got the win."
The three points keeps West Ham in the top four and the No13 has been delighted with the team's start to the campaign.
He added: "The new signings have been top class and we've got a very good group. The most important thing in football is the team, and we're attacking and defending as a team.
"We need to keep on going this way, step-by-step, but enjoy the situation now!"