Robbie Neilson was impressed with his side's desire in extra time as they saw off Charlton Athletic 3-1 at Stadium MK on Tuesday night to progress into the FA Cup third round.
After Daniel Powell's seventh minute opener was cancelled out by Adam Chicksen's 24th minute equaliser, both sides butted heads in an evenly-fought contest, sending the game into extra time.
REPORT: MK Dons 3-1 Charlton Athletic: Extra time goals book Dons a third round spot
But it took just four minutes for Ben Reeves to fire Dons back in front before he set up Dean Bowditch to score his ninth of the season and wrap up their second home win in three days.
After an intensive 1-0 win over AFC Wimbledon on Saturday, many suspected a weary MK Dons side to take on Charlton, but after 90 minutes, Neilson asked for one more kick from his side, and he felt he got it.
"That first 10 minute period, you have to stamp your authority on extra time," he said. "When it gets to that stage, it's not about who has the best players or technique, best squad, but who wants it the most.
"It was a tough game, coming off the back of such a tough one on Saturday. Sometimes you have the come down afterwards.
"It was about working hard and fighting. I asked them at the end of 90 minutes to go again, and it would be a defining moment. Would they fight and go again and get a result or crumble?
"To be fair to them, they showed they had spirit and energy. We got two quick goals and saw it out.
"They'd feel a lot more tired tomorrow if they'd have lost. After winning a game like that, mentally they'll be ready for the next one."
Dons keeper Lee Nicholls sent the tie to extra time by denying Charlton's Nicky Ajose with a fine stop in the final minute. And Neilson said he needs every player to step up as the fixtures come thick and fast.
He said: "We need everyone to do their part - the keeper, the defence to keep them out, midfield and strikers to go and press. To a man, everyone played their part again."
While his squad looked like the walking dead come the final whistle, there were concerns for George Baldock, who hobbled off early in the second half.
Neilson though calmed fears and said he would probably be fit for Saturday's trip to Gillingham.
He added: "(George) hadn't been feeling well for a week. He gave everything on Saturday, then again tonight but felt queasy. He took a bad knock too, so we felt it was better to take him out and protect him for Saturday."