BOSTON — Ray Allen picked the perfect time to snap out of his shooting slump.

Allen made a tiebreaking 3-pointer with 2 seconds left and finished with 30 points, leading the Boston Celtics a 118-115 win over the Chicago Bulls in Game 2 of their playoff series Monday night.

Ben Gordon nearly carried Chicago to a 2-0 lead in the best-of-seven series. He scored with 12.3 seconds left to tie it, and had a playoff career-high 42 points. Then Boston set up a play for Allen, who took a pass from Rajon Rondo and connected from the right side.

Allen had just four points on 1-for-12 shooting in Boston's 105-103 overtime loss on Saturday and missed the final shot.

The next two games of the series are scheduled for Chicago on Thursday night and Sunday.

Allen scored 28 points in the second half, which turned into a shootout between the All-Star guard and Gordon.

Consecutive 3-pointers by Gordon gave the Bulls a 109-104 lead before the Celtics rallied. Glen Davis made two free throws and Rondo connected on a long jumper to give Boston a 112-111 lead with 1:01 to play.

Gordon followed with a 16-foot jumper and Allen countered with a 3-pointer that put Boston ahead 115-113 with 25.3 seconds remaining.

Then it was Gordon's turn. He connected from near the foul line before the Celtics called a timeout to set up their final play.

Rondo dribbled on the left side and Allen worked himself free, caught the pass in rhythm and converted as the crowd went wild. Tyrus Thomas then heaved a shot from beyond midcourt that fell short.

Allen ran to the bench where injured Kevin Garnett, wearing a sport coat and tie, slapped him on the head and chest. On his way to the locker room, coach Doc Rivers shouted, "yeah, yeah," pumped his fist and exchanged high-fives with fans.

Then, headed to his postgame news conference, Rivers joked, "nice and easy, never a doubt."

Glen Davis had 26 points for second-seeded Boston, passing his career high of 24 points on March 21, and Rondo had a triple-double — 19 points, 16 assists and 12 rebounds. Paul Pierce added 18 points and Kendrick Perkins contributed 16 points and 12 rebounds.

John Salmons had 17 points and Brad Miller scored 16 for Chicago.

The Celtics nearly lost despite controlling rookie point guard Derrick Rose. He finished with 10 points, seven assists and six rebounds after leading the Bulls with 36 points and 11 assists on Saturday.

Rondo missed the last 5:03 of the first half with a minor right ankle sprain but returned to start the third quarter. Backup forward Leon Powe didn't return to the bench after going to the locker room early in the second quarter. He hobbled away but there was no announcement of his injury.

Notes: Garnett spent the entire game on the bench, mostly standing. In the opener, he was there for the first half but stayed in the locker room after intermission. ... Gordon's previous playoff high was 35 points. ... The game was played on the 23rd anniversary of Michael Jordan's NBA playoff record of 63 points. Boston beat Chicago 135-131 in double overtime. ... Red Sox pitchers Josh Beckett, Jon Lester and Justin Masterson attended the game. Masterson was the winning pitcher in a 12-1 victory over Baltimore on Monday, allowing one run in 5 1-3 innings. ... Boston Celtics owner Wyc Grousbeck was at the game after finishing the Boston Marathon earlier Monday in 4:16:49. He sat next to New England Patriots owner Robert Kraft.