Wasps' director of rugby Dai Young conceded that his high-flying side were second-best as they crumbled to a 30-19 defeat against London Irish at the Madejski Stadium.
Tom Homer kicked 20 points as the Exiles recovered from 14-16 down at half-time to claim a comfortable victory, and Young said: "We were never in control of that game.
"In the first half they dominated but we took our one opportunity to score to lead at the interval.
"After that we were looking to gain footholds in the Irish half but they prevented us from doing so.
"We badly missed Billy Vunipola today as we lacked penetration and we looked a very tired side and we were one-paced."
Irish director of rugby Brian Smith added: "I'm delighted to get the win as we felt we needed to win all our home games.
"Since we spoke we've beaten Saracens and Wasps at home and we have three more against the bottom sides to go.
"After last week's poor effort at Gloucester, the pack had a point to prove and the game was won up front.
"After his yellow card Chris Hala'ufia felt he owed the team and he came up with the game-breaking run for Marland Yarde's try which was the crucial turning point in the match."