BOSTON (AP) Cleveland's third quarter was unacceptable to LeBron James. The fourth period was much better.
James and Kyrie Irving helped the Cavaliers rally for a 122-121 victory over the Boston Celtics on Friday night. James had 10 of his season-high 41 points in the fourth, and Irving scored 15 of his 27 in the final quarter of Cleveland's third straight win.
Perhaps most importantly for the Cavs, they held Boston to 20 points in the final 12 minutes after allowing 42 in the third.
''We gave up a 40-point quarter and that's unacceptable if we want to grow,'' James said, ''but we showed growth in the fourth quarter.''
James made one of two free throws with 36 seconds left to give Cleveland the lead. The Celtics then lost the ball out of bounds, but Irving missed a layup and Avery Bradley rebounded for Boston, which called timeout with 7 seconds to go.
Rajon Rondo, who finished with 16 assists, then lost control of his dribble near the top of the key. He shot and missed just after the final buzzer.
''We had a couple of different options,'' Celtics coach Brad Stevens said. Rondo ''had a good matchup, but Joe Harris did a nice job on him.''
Kevin Love added 12 points and 15 rebounds for the Cavaliers.
''That's quite a homecoming,'' said Cleveland coach David Blatt, who grew up in nearby Framingham. ''I thought Boston played great basketball for three quarters (and) we waited a long time to get it in gear defensively.''
Kelly Olynyk led Boston with a season-high 21 points, and Jared Sullinger and Jeff Green had 19 apiece.
Boston grabbed a 103-84 lead on Tyler Zeller's layup early in the fourth quarter.
Then Irving took charge, scoring 13 of Cleveland's next 15 points and cutting the margin to 107-99 with 8:40 left.
James led the Cavaliers in the last six minutes of the quarter with 10 points. His three-point play put them ahead 120-118 with 1:11 remaining before Love added a free throw.
Boston then tied the game at 121 on one free throw by Sullinger and two by Green.
''Kyrie made some shots. LeBron made some shots,'' Sullinger said. ''That's what great players do.''
Coming into the day, Cleveland had allowed the sixth-highest average points in the NBA, while Boston gave up the fourth most.
The first half ended with the score tied at 59. Neither team led by more than three points in the last eight minutes.
THREE AT A TIME
Irving made three 3-pointers in the first three minutes of the fourth quarter.
''The problem is, if you defend him differently, you're going to give up something else,'' Stevens said.
HOT AND COLD CELTICS
Boston missed just six shots while outscoring Cleveland 42-25 in the third quarter, but then went 8 for 16 from the field while getting outscored 38-20 in the fourth.
''We'll have a chance to be very, very good'' with consistent defensive play, Blatt said. ''Until we do, we're going to have to win games like this.''
Cavaliers: James had his first shot blocked by Olynyk but finished the first half with 22 points. ... James passed former Celtics star Robert Parish for 24th place in career scoring with 23,360 points. Parish scored 23,334. ... G Dion Waiters came off the bench after missing Monday night's win over New Orleans with a bruised lower back.
Celtics: Seven Celtics scored in double figures. ... G Marcus Thornton returned after missing Wednesday night's loss to Oklahoma City with a sprained right ankle.
Cavaliers: Return to Cleveland to face Atlanta on Saturday night, beginning a stretch of eight games at home in their next nine.
Celtics: Finish a three-game homestand Monday night against Phoenix.