BOSTON – Linsanity in the fourth quarter.

Rondomania in overtime.

Rajon Rondo had his second triple-double in three games, finishing with 18 points, 20 assists and a career-high 17 rebounds, as the Celtics ruined Harvard grad Jeremy Lin’s return to Boston with a 115-111 victory over the New York Knicks on Sunday.

Rondo played a part in every Celtics point in overtime, collecting five points, five rebounds and two assists in the extra period.

“I know we’re all in this together, but it’s great when he takes over like that,” Celtics Coach Doc Rivers said. “He’s the smartest point guard I’ve ever been around. He’s a brilliant player like that.”

Paul Pierce scored 34, including a 3-pointer with 4.9 seconds left in regulation. Kevin Garnett had 18 points and 10 rebounds, and Ray Allen gave the Celtics the lead for good with a 3-pointer to make it 108-105, then followed it with a fast-break layup — both on assists from Rondo.

Rondo also had two baskets in overtime, and he even made the pass to Brandon Bass before he was sent to the line for two free throws.

It was Rondo’s fourth triple-double this season and the 17th of his career.

According to the Elias Sports Bureau, the last player to record a triple-double with at least 17 in each category was Magic Johnson, who had 24 points, 17 assists and 17 rebounds on April 18, 1989. The last player to exceed Rondo’s performance in each category was Wilt Chamberlain, who had 22 points, 25 rebounds and 21 assists on Feb. 2, 1968.

“That’s the Rondo we like to see, playing with all that energy,” Pierce said. “He got the guys the ball in open spots; he did everything for us tonight. He rebounded, he passed, he got the clutch rebound there in overtime and got the layup.”

Lin picked up two fouls in the first three minutes and struggled to 14 points in 32 minutes. He had five assists, four rebounds and six turnovers.

Carmelo Anthony scored 25 for the Knicks, six of them in the final 100 seconds of regulation as they twice took the lead. Amare Stoudemire had 16 points and 13 rebounds, and Tyson Chandler grabbed 14 boards, but New York still fell a game below .500 and 11/2 games behind Boston in the Eastern Conference.

“It was a big win for us,” Rondo said. “We’re trying to get a little separation.”

The Celtics and Knicks entered with 18 wins each. Boston now leads the season series 2-1, with one game remaining in New York on April 17.

Boston led 94-89 with 3:35 left in the fourth quarter when Lin sank the second of two free throws, stole the ball and took it in for a layup and then hit a 3-pointer to cut the deficit to one point.

Anthony took it from there, making the next three Knicks baskets and giving them a 101-100 lead with 36 seconds left. Pierce missed one attempt at a winner, but after Steve Novak made two free throws Pierce sank a long, off-balance 3-pointer to tie it at 103.