Perry Kitchen, left, of D.C. United battles New England’s Fernando Cardenas for the ball at RFK Stadium. United won, 3-2, on a goal in the 61st minute by substitute Maicon Santos to move into first place in the MLS’s Eastern Conference. (Patrick McDermott/Getty Images)

D.C. United forward Maicon Santos entered Saturday’s contest against the New England Revolution as the team’s leading goal scorer. He also started the game on the bench.

The options are more plentiful for United this season. And so with an opportunity to move into first place in the Eastern Conference for the first time in three years on Saturday night, Santos watched the beginning from the sideline.

This is the new-look United. One that has the luxury of bringing on its most effective goal scorer this season when a two-goal lead evaporates in a five-minute span in the second half, and then to see him score just five minutes later to provide the final margin in D.C.’s 3-2 win.

Santos’s super-sub game-winner at RFK Stadium provided yet another peak at the transformed United (8-4-3), which has won three consecutive league games for the first time since June 2008 and sits atop the conference table for the first time since July 2009.

“It’s strange,” United Coach Ben Olsen said. “Because I feel unfulfilled. I think our team feels unfulfilled right now.”

Yes, most certainly a different United.

That changed attitude felt as evident as ever, defender Brandon McDonald said, not when the team built a 2-0 lead in the first half, but when they saw it disintegrate in the first five minutes of the second half.

Goals from New England’s Saer Sene in the 48th minute and A.J. Soares in the 50th flipped a confident United on its head, it seemed.

“I wasn’t worried,” McDonald said. “It was weird. Because last year, they get two goals I think we’re going to lose this game, 5-2.”

Looking for a spark, Olsen turned to Santos, who had six goals in the first nine games of the season but had not found the back of the net since a 3-2 win over Houston on April 28.

The Brazilian entered and soon found the ball near the left side. He played Dwayne De Rosario into the box and cut toward the middle, where the reigning league MVP laid it back in for Santos’s right foot, and the forward buried it.

It was De Rosario’s league-leading eighth assist of the season.

“Thankfully, we have the depth of every guy ready to step in to make a difference,” De Rosario said.

With Santos sitting and Chris Pontius (five goals) still unavailable with an ailing hamstring, nearly half of United’s goal production this season was not in the starting lineup.

Never mind that. D.C. fielded a team against New England (4-7-1) that appeared as menacing as ever, with proven threats throughout its front five.

Then, of course, United got goals in the first half from its two central defenders, McDonald, who averages one per season, and Dejan Jakovic, his first career finish, to take an early 2-0 lead.

Both were the beneficiaries of fantastic service from midfielder Branko Boskovic, who has had as up and down career with United as any other player. The Montenegro international had not registered a point in his first 25 appearances with United and now, two assists in his last two games.

“After my two seasons here every time we were up and down,” he said. “Now first time we look like a real team.”