Kiernan Dewsbury-Hall's second-half strike was enough for Luton to win at promotion-chasing Bournemouth, who played for more than an hour with 10 men.
Midfielder Jefferson Lerma was controversially sent off for the hosts when he inadvertently caught Hatters defender Tom Lockyer in the face with a flailing arm after being knocked off balance in the air by Luke Berry.
Despite being a man down the Cherries matched their visitors, Joshua King's volley being parried wide and Dominic Solanke's effort cleared off the line by Dan Potts.
But Luton also had their chances and took all three points as on-loan Leicester midfielder Dewsbury-Hall curled a low shot into the far corner from the edge of the area.
Victory lifts Nathan Jones' Luton into the Championship's top half while Bournemouth remain third, eight points behind leaders Norwich with the chasing pack closing in on them.
Lockyer was forced off for the visitors shortly after the incident that led to Lerma being red carded but the Colombia midfielder could do little to avoid the unfortunate coming together, with Cherries boss Jason Tindall clearly unhappy with the officials at the interval.
Luton looked to make the man advantage count after the break, Glen Rea going close before Asmir Begovic made a superb double save to keep out efforts from Berry and Dewsbury-Hall.
The talented young midfielder did make his mark though, receiving the ball in space from Harry Cornick and guiding it around a Bournemouth defender into the net.
Late substitute Rodrigo Riquelme came closest to a leveller for the home side but his volley was tipped away by Simon Sluga as the Cherries lost a Championship match on a Saturday for the first time this season, adding to the frustration of Tuesday's home draw with Millwall.
"It [Lerma's dismissal] was an outrageous decision, I think everybody knows it, even their staff, their players, our players.
"I don't think the ref was going to give a red card, I honestly believe he wasn't, and then he has reacted to a bit of blood on their player and made the decision, but he certainly couldn't have seen the incident to have made the decision that he's made.
"You expect the assistants and the other guys to maybe help with certain decisions, but I have found that in this division they don't seem to get too involved and work as a team.
"For us it proved to be a really crucial moment in the game, although I still believe we were by far the better team all day today."
"To be fair it [Lerma's red card] seemed to rock us more than them, they galvanised a little bit, came after us and were a real, real test.
"But we got into half-time, we changed a few things, and I thought second half we were excellent.
"They have good athletes, they have players that are too good for this level so for us to compete we need something to go for us, and it did today."