Robbie Neilson believes the FA Cup win over QPR will pale into insignificance compared to their League 1 clash with AFC Wimbledon next weekend.
Ouss Cisse scored the only goal of the game as MK Dons beat Championship QPR at Loftus Road on Saturday to book their spot in the fourth round.
READ THE REPORT: QPR 0-1 MK Dons
But with a crunch relegation six pointer against bitter rivals AFC at Stadium MK next Saturday, Neilson said the FA Cup win is a nice distraction, but the league game is the biggest game of the season to come.
"It's a big win, we're into the next round, but it means nothing because of the game next week that's even bigger than this," he said.
"It's the biggest game of the season for us. I'm delighted, it's great to go through but the biggie is next week.
"The cup run builds momentum, spirit and gives the fans a day out and gives us a chance to play some of the younger lads too. We want to go as far as we can but the league is the most important for us."
Dons weathered a second half storm as QPR, who made just one chance to their regular Championships side, threw everything they in a bid to take the lead before Cisse fired the visitors in front on the hour.
Like against Peterborough last weekend, Dons withstood the late barrage of chances for the hosts, and seven minutes of stoppage time, to see out the win.
Neilson said: "We had this spirit in the Peterborough game too. We need to get better at is when we're on top and then flip into a defensive phase. It';s in the transition. We speak about it, we'll work on it and we need to carry that on for the rest of the season.
"If we can do that, we'd be in and around the play-offs, but we have to emulate that. We need to improve the negative sides of our game.
"I'm delighted for the fans, players and the owners of the club today. We've had a tough period in the league. Hopefully we can use this form and the togetherness into the AFC game next week.
"I thought we were in the ascendancy in the first half. But our back four was excellent. Everyone to a man did that we asked them to do.
"We came in at half time and knew the game would air in their favour as they hunted for a goal, but we stood firm. We defended so well and put bodies on the line."