Wednesday's captain pleased with manner of cup victory
A dominant display from the hosts set up a tie away to Everton in the last 16 of the competition, with second half strikes from Matt Jarvis and Kyle Lafferty helping to secure victory against the Baggies.
Having captained the Canaries in the absence of Russell Martin, O'Neil told Norwich City TV: "It was good night for me and it was nice to be given the responsibility by the gaffer.
"I enjoyed it and the lads were great. It was a fantastic team performance against Premier League opposition so we’re really pleased to get through to the next round.
"When you make a lot of changes it can be tough sometimes to find a pattern with people. However, we've been together as a group for a while and were right at it from the start.
"We probably should have made it a bit easier by going in front earlier on but we stuck in there and got a convincing win in the end."
The former West Ham United midfielder also credited the performance of recent recruit Jarvis, who O'Neil played alongside during his time at The Boleyn Ground.
Jarvis' form since arriving in Norfolk is no less than was to be expected according to the 32-year-old, who added: "It doesn't surprise me how well he's doing because he's a good player.
"I knew he'd suit us because we needed some out-and-out width, and he's a typical old-fashioned winger. He works the full-back's very hard and looks to get crosses in.
"That can open games up for us. Hopefully he can keep going as it's been a good start for the team.
"We've worked hard as a group and come away with good results from most of the games we've been involved in."