Cardiff City manager Steve Morison told BBC Sport Wales: "It was disappointing because we dominated the game from start to finish.
"We gave a couple of chances away and they took them; the second one was offside but that's life.
"As a team we didn't finish our moments of good play off and they did.
"There are lots of ifs, buts and maybes but the only thing we know for sure is we lost the game."
Luton Town manager Nathan Jones told BBC Sport Wales: "I love coming to Wales, when we come here we get results and we've been excellent.
"I love coming here, I'm a Cardiff fan, and I'm really happy to get the win and I think we deserved it.
"Second half we were excellent, we're unlucky not to win by more."