To Doug Collins, Boston's Big Three is already a memory.

"I don't look at them as the Big Three. I look at them as the Championship Four," the Philadelphia coach said. "Because if you're going to leave Rondo out, you're making a huge mistake."

Rajon Rondo helped his ageing teammates keep their season going on Saturday night, finishing with 18 points, 10 assists and 10 rebounds in Game 7 against the 76ers to lead Boston to an 85-75 victory and into an Eastern Conference finals matchup with the Miami Heat.

The Celtics will open the third round of the NBA playoffs in Miami on Monday night.

"I've already packed," Celtics coach Doc Rivers said. "We'll be ready. It's going to be a tough turnaround, but we're not an excuse team. We'll be ready on Monday."

Bouncing back from his worst game of the playoffs - and snapping out of a 32-minute slump in which he had just two assists and five points - Rondo scored nine straight Boston points after Paul Pierce fouled out to help the Celtics turn a three-point edge into a double-digit lead.

Rondo had 11 points in the fourth quarter, including his first 3-pointer in five games, made all four of his free throws down the stretch and grabbed his 10th rebound in the final seconds - chucking it over his head and into the frontcourt to help the Celtics dribble down the clock.

"He really came through," Sixers guard Jrue Holiday said. "He put the team on his back."

Andre Iguodala scored 18 points and Holiday and Elton Brand had 15 apiece for the 76ers, who eliminated the top-seeded Chicago Bulls in the first round but couldn't do the same with the Celtics.

Kevin Garnett had 18 points and 13 rebounds for Boston, and Ray Allen hit a pair of fourth-quarter 3-pointers after missing his first five attempts.

"Ray is the ultimate gunslinger," Rivers said. "That's what makes great players great. I was a basketball player ... and I would have never taken that shot."

Pierce had 15 points and nine rebounds before fouling out with 4:16 left.

That's when Rondo took over.

The point guard, who had nine points and a playoff-low six assists in the Game 6 loss in Philadelphia, scored on a baseline drive and followed it up with a long 2-pointer (originally scored a 3) with 2:47 left. Then he made a 3-pointer with a little more than two minutes left to make it a 10-point game and, after Brand scored on a tip-in, Rondo went to the line as the crowd chanted "M-V-P! M-V-P!" and hit a pair of free throws to leave Boston with an 80-70 lead with 1:44 left.

The Celtics will now face the actual NBA MVP - LeBron James - along with Dwyane Wade and the rest of the Heat. Miami advanced to the conference finals by eliminating the Indiana Pacers in six games.

Miami beat Boston in five games in the conference semifinals last year. In 2010, the Celtics eliminated the Heat in the first round and then knocked James and the Cavaliers out in the second - his final game with Cleveland before defecting to Miami.

"Last year is in the past," Rondo said. "This year we're a totally different team. We feel we can beat Miami. We got to this point; there's no doubt in my mind we can. We've got to go down there and take care of business."

Associated Press in Boston