DeLeon scored in the 88th minute, Willis had a crucial save on a penalty kick and D.C. United advanced to the Eastern Conference final with a 1-0 victory over the New York Red Bulls on Thursday night.
United advanced 2-1 on aggregate after playing New York to a 1-1 draw Saturday and faces the Houston Dynamo in the conference final.
In a game that was postponed a day after a Nor'easter blanketed the field with snow Wednesday night, the Red Bulls appeared poised to take the lead in the 69th minute when they were awarded a penalty kick as D.C. United's starting goalie, Bill Hamid, was given a red card.
In a wild series of events, the Red Bulls scored a goal that was taken back before Willis made a stop on the second attempt. Kenny Cooper put his initial penalty kick past Willis, but the goal was called off by the referee because the Red Bulls had entered the penalty area early.
Willis, apparently warmed up after the first attempt, dove to his left on Cooper's second penalty kick and made the save. Cooper decided to go to his right and was thwarted by Willis. His first kick had beaten Willis to the other side.
"The first one, I went the wrong way, but, hey, they didn't count that one," said Willis. "After it went in, I tried to clear my head. It's a different kind of PK when they call the first one back. It's even more of a mental game. There is always more pressure on the kicker."
Cooper, who took a last-second hop before he struck his two kicks, may have caused his teammates to encroach with the hesitation in his approach. Cooper was too distraught to talk after the game, fighting back tears while sitting at his locker.
It was a wild finish to a game mostly dominated by the Red Bulls, who were repeatedly thwarted by Hamid.
"Mostly when it's New York as the opponent," D.C. United coach Ben Olsen said when asked if he had been involved in such a game. "It's an absolute zoo these games."
Willis had turned and smiled as he ran onto the field, receiving some last-minute advice from Olsen.
"I told him to make a save and he made a save," Olsen joked. "I'm a genius. He hasn't played a game in a long time. He only plays when Bill (Hamid) gets red cards. He's a big boy and we have a lot of faith in him."
Red Bulls coach Hans Backe had nothing but praise for Cooper.
"He scored on the first one," said Backe. "He has no problem with taking penalty kicks. He's a calm, cool, guy. Mentally, he has no problem with it."
The Red Bulls had a man advantage after Hamid's red card until the 75th minute when Rafa Marquez received his second yellow card and was ejected.
"We deserved to win the most and we didn't," Red Bulls striker Thierry Henry said. "You have to give D.C. credit. We missed so many chances. They scored and we didn't. I don't know how many chances we had, but we didn't score."
The penalty kick was set up when Henry connected with Dax McCarty, whose through ball sent Cooper on a breakaway. Hamid came off his line to challenge, but when Cooper pushed it past him, the keeper reached out and tripped Cooper. The red-card ejection followed and Cooper waited at the penalty spot for Willis to take his place in goal.
"It was a leap," Hamid said. "I watched the replay and (Cooper) made a leap over me. He wasn't touched."
Robbie Russell's through ball sent DeLeon in on goal alone and he put his chance away past Red Bulls keeper Luis Robles, who was hardly tested all game.
The Red Bulls announced before the game that they would donate half of the ticket receipts, a total of $250,000, to hurricane relief funds in New Jersey and New York, as well as the Red Cross.