Braces from Sebastien Haller and Andriy Yarmolenko at London Stadium, arriving after Robert Snodgrass had opened the scoring against his former club in the first half, granted the Hammers safe passage into the Carabao Cup fourth round.
“I'm absolutely delighted," Irvine surmised. “I think to a man they played extremely well, with three young players who ended up making debuts tonight. They all did extremely well, and the senior players helped them through and did a great job for themselves as well, so I'm absolutely thrilled with how the team played.
“I felt that right from the beginning of the game our work-rate was fantastic, our organisation was fantastic, the way that players filled in for each other was great, and I said to them in the dressing room before the game that that work gives you the platform to show what you're capable of doing."
Irvine added: "These games are an opportunity for the boys who aren't at the moment playing in the first-team starting eleven.
“They have to grab these opportunities when they come along, and I have to say they have done, as have a number of the other players."