"To come away to a tough place like this, get the three points, but the way we did it as well was excellent.

"In possession, out of possession, the way we moved the ball, the chances we created, the way we defended as a unit, for me that's the best performance I've ever witnessed from any of my teams since I've been a manager.

"That was excellent because their manager, the one thing that his group always does is they work hard for him.

"We had to compete and match that and we did that plus more, so I'm delighted with three points and the way we performed.

"It's not just the defenders, it starts from the front.

"I took two strikers off because they were shattered, not for any other reason.

"Scott Hogan I would have loved to have kept him on to try and get a hat-trick but he couldn't run anymore so that's why we keep clean sheets because as a group we work hard and try to do the right things.

"If we keep doing that then we'll be okay this season."

Roberts put City ahead after just seven minutes with a powerful header from a corner before Hogan made it 2-0 after 26 minutes, directing his header from Tahith Chong's cross past Simon Sluga.

The Hatters created little during the first period, Tom Lockyer being denied by keeper Matija Sarkic twice, as City's third arrived two minutes after half-time as Chong outpaced the hosts defence, allowing Hogan to tap home.

Although Cameron Jerome went close against his former club, with Fred Onyedinma flashing across goal, Birmingham ran riot late on as substitute Gardner arrowed a shot into the top corner after 84 and a prostrate Aneke adding a fifth with two minutes to go.

Luton boss Nathan Jones added: "I'm really disappointed, a little bit embarrassed by the scoreline and the level of performance but I don't often get that from this group in terms of being embarrassed.

"I'm always proud of them, they give me everything, today we shot ourselves in the foot from early on.

"We conceded from a set-play which we did last weekend as well, it sets you back.

"Ironically we started the game so well on Tuesday (against Barnsley), we wanted to continue that, but we didn't do the basics well enough today and that's what caused us problems.

"As I said, I'm embarrassed a little bit by the scoreline but we have to learn from that and go again.

"We've got a lot of people out that we regard as our best headers.

"We've got two six foot two, three, four, five foot centre-halves out, Dan Potts who's arguably our best header is out, so we've got a lot of people who do the basics well out."