Nathan Jones said Luton's shock 1-0 win at 10-man Swansea crystallised his belief the Hatters can secure Sky Bet Championship survival.
Luton moved off the bottom of the table at the Liberty Stadium as James Collins' second-half header gave Jones' men what could yet be a priceless three points.
Swansea had an afternoon to forget and home substitute Jordan Garrick was sent off in the 83rd minute for a punch on Collins.
"We thoroughly deserved it. To come here as the away side and with Swansea flying high means it's a wonderful result," said Luton boss Jones.
"We had belief we could stay up before we came into this game, but we have to instil it with results. Results rubber-stamp the belief and that's what today will do.
"If we had no belief, why come here? I could have stayed in my garden and had a barbecue. We believed we have enough in this squad. Now, we have to pick up the points to prove that.
"We came here to win. As an away performance from a team at the bottom of the league, it was an outstanding display. Swansea have a front four as good as anything at this level, so we had to be tight and subdue them. We did that."
Swansea were off the pace from the first whistle and Luton had the first half's best chance. Harry Cornick broke away down the right and cut inside but blazed his shot wide.
Garrick replaced the wasteful Aldo Kalulu at half-time and Swansea were better as a result, but they had only three shots on target all afternoon.
Luton won it in the 72nd minute. Hatters substitute Izzy Brown crossed from the right, Collins rose high above Ben Cabango and his powerful header was too much for Freddie Woodman.
Swansea's frustration boiled over when Conor Gallagher and George Byers made wild challenges which prompted a scuffle. Garrick swung a punch at Collins and was sent off.
Steve Cooper admitted his Swansea team's play-off chances had been severely dented by this result. For Luton – unbeaten in their last five games – victory followed last weekend's draw with Preston.
"We've only got ourselves to blame. It was a poor result and a poor performance. We didn't see that coming," Cooper said. "Once the game started, I didn't like our attitude towards it.
"When you start like that, it's difficult to shake it off. It will cost us because points are so important at this stage of the season. We don't want to be relying on other teams."
Cooper described Garrick's dismissal as a "clear red card", while Jones focused on the task ahead.
"We have to get to a points tally and keep things in our hands. We go to Leeds now, which is mammoth," said Jones.
