A backup goalkeeper and a rookie took down the mighty New York Red Bulls on Thursday night.

And Thierry Henry just stood and watched as the season ended for New York.

Joe Willis came off the bench after starting goalie Bill Hamid was sent off to save a penalty and rookie Nick DeLeon scored in the 88th minute as D.C. United edged New York, 1-0, to advance to the Eastern Conference final.

"It's unbelievable," DeLeon said. "I'm speechless."

United and New York tied, 1-1, in the first game at RFK Stadium, and a victory in he return match at Red Bull Arena - postponed one day by a snowstorm - gave D.C. a 2-1 aggregate win in the series.

D.C. will visit the Houston Dynamo on Sunday in the first match in the Eastern Conference finals. The second leg will be Nov. 18 at United.

After blizzard-like conditions forced the postponement of the match Wednesday, 14,035 fans returned to RBA for what turned out to be an epic second leg.

After a scoreless first half that saw New York enjoy more scoring chances, the Red Bulls continued to be the better side early in the second half.

Hamid was busy for D.C., and made his biggest saved in the 65th minute when he denied Dax McCarty from close range with a save with his left arm.

Four minutes later, a wild final 20-plus minutes started with Hamid getting a red card from referee Mark Geiger for a challenge on Kenny Cooper on the edge of the penalty area.

Hamid protested the call and, after a lengthy delay, Cooper stepped up to take a penalty against backup Willis. Cooper buried the first shot, but the attempt was called back by Geiger because New York players entered the area too early.

Willis guessed correctly on the second try from Cooper, a perfect 10-for-10 in his career from the spot, and dove to his left to save the penalty in the 74th minute.

"We had a similar situation last year (against Cooper). He went one side, got called back and he went the other side," Willis said. "I was lucky (assistant) Pat (Onstad) reminded me of that before the game and I was lucky that I made the save."

New York only enjoyed its man advantage for about one more minute.

Rafa Marquez earned his second yellow card of the game for a poor challenge on Chris Pontius in the 75th minute, leaving both sides with 10 men.

United followed with the winner during a frantic finish, as right back Robbie Russell found DeLeon in the right side of the area, and the rookie turned and fired a first-time, right-footed shot to beat Luis Robles at the near post.

New York had one last-gasp chance off a free kick from just outside the area, but with Henry and Roy Miller both over the ball, Miller launched the chance well high as Henry - one of the greatest strikers in the world - just stood a few feet to his side and watched.

"We talked about it or so with Roy and we wanted to surprise the goalkeeper; make him think that I was going to take it and then Roy take it," Henry said.

While United will continue its quest for a fifth MLS Cup, New York was left to ponder another missed opportunity, as it will remain without an MLS Cup for at least one more season.