Just when it looked like Minnesota United was about to escape with a hard-earned win amid an exhausting stretch of games, one in which the Loons players got wore down, nicked up and spent, FC Dallas had an answer.

A penalty kick was awarded to Dallas in the final minutes of stoppage time Saturday. Save it and it's a fourth straight win for the Loons. Yield the goal and the visitors escape with a tie.

Goalkeeper Vito Mannone didn't flinch. He dived to his right and stopped Reto Ziegler's attempt to tie the score, simultaneously hand-delivering a thrilling 1-0 win for the Loons.

"A penalty is the chance for a keeper to become the hero," Mannone said. "That's how I feel it every time. I looked at that ball, I thought, 'This is my moment. This is my one.' "

After all the drama, chippiness and stress, the result was an MLS win and another three points in the standings. For coach Adrian Heath and a club battling to make its first appearance in the playoffs, it was monumental — and maybe even historic.

"It's the biggest win I've had since I've been here," Heath said. "For what it means to everybody. You saw the reaction from the players, you saw the reaction of the supporters. Incredible effort from the boys. Incredible. And I know how tired they are."

Mannone's heroics wouldn't have mattered without forward Mason Toye's goal in stoppage time. It's the second straight MLS game in which the 20-year-old netted the game-winner for the Loons, knocking in a rebound off Dallas goalkeeper Jesse Gonzalez.

The victory meant so much because the battered Loons are barely stringing along, Heath said. Minnesota's attack has been one of the deadliest in the league the past few weeks, totaling 26 goals in the six games leading to Saturday. But sloppy play and tired legs proved to be the Loons' downfall in the first 90 minutes against Dallas.

"I don't know how much it was they were doing stuff well, I think it was we weren't playing the greatest," Toye said. "Obviously, we've been playing so many games, the guys are pretty tired."

Before Toye's goal, the Loons were beset by missed opportunities, the ball trickling harmlessly away from the goal and Gonzalez.

In the 87th minute, right when it looked like Minnesota was about to break through, Ike Opara's bouncing shot barely missed the goal. But the Loons kept the pressure on the visitors, and eventually Dallas cracked.

The victory was the first time Minnesota didn't score at least three goals since June 8, a 1-0 loss to Colorado.

Minnesota is near the end of its stretch of seven games in 22 days. Heath said he was worried coming into Saturday, fearing the mental and physical grind was getting to the players.

Despite the coach's best efforts, for 90 minutes nothing seemed to work. And still the Loons gutted out a victory.

"So proud of the players," Heath said. "They were running on empty today. Our resolve and determination not to lose the game was immense."

Minnesota United's Vito Mannone celebrates after saving a penalty kick in stoppage time against FC Dallas (Brian Stensaas — Star Tribune/The Minnesota Star Tribune)