The Liberian striker notched both goals to give United a 2-1 win over the visiting New England Revolution on Thursday.
"We worked hard in training, and we had a feeling something good would happen today," Doe said. "It was a team effort."
United's win catapulted it to fourth place in the Eastern Conference and into the first wild card berth; however, it's still uncertain whether the team will reach its seventh consecutive postseason. United can control only so much of its fate with one game left in its season.
United's playoff aspirations looked dashed when former Maryland star Taylor Twellman scored his 15th career goal against the club to give the Revolution the lead in the second half. United tied the game when veteran striker Jaime Moreno came off the bench and set up Doe's first goal with his 10th assist of the year.
"When Jaime came on, he changed the game," United midfielder Santino Quaranta said.
Then with 10 minutes remaining, Doe battled his way into the Revolution's goal area to score the game-winner.
"I had to use my strength and speed because of [Revolution defender Michael] Parkhurst," Doe said. "He's a fierce player."
Now United has to hope other results go its way in the next 10 days, and it has to win its last game at the Columbus Crew on Oct. 26. The Crew has clinched the Supporters' Shield, which is awarded to the team with the league's best record.
The victory snapped a seven-game winless streak (0-4-3) in league games for United.
Doe played aggressively throughout. In the 19th minute he dribbled into the box and tested Revolution goalie Matt Reis. United was the more offensive team in the early stages. However, in the 25th minute United goalie Louis Crayton had to make a stunning save to punch out Mauricio Castro's powerful free kick.
United came close to scoring when Emilio's header bounced off the bar after he had connected on a cross from Thabiso Khumalo.
Then the Revolution took the lead on a breakaway attack in the 58th minute. Castro ran down the right flank and passed to Twellman, who scored his 99th career goal.
United coach Tom Soehn then sent in Moreno. The leading scorer in MLS history set up Doe for the tying goal in the 63rd minute. Moreno fed the ball to Doe running in the box. Doe beat a defender and placed a shot past Reis for the club's first goal in four games.
Soehn then sent in Fred for Khumalo to search for the winning goal. It nearly came when Fred set up Quaranta, but the midfielder blew the chance. Quaranta redeemed himself by heading a ball from Crayton's long kick into Doe's path. Doe fought his way into the Revolution's box to beat Reis and give United the lead in the 80th minute.
"With Francis it's very easy," Soehn said. "He is working very hard, and when you do all the little things right, the goals come with it. He's putting pressure on defenders and competing, and if he continues to do that he's a hard player to play against."