BOSTON (AP) — Celtics coach Brad Stevens didn’t get carried away by Boston’s rout of a Cleveland team that bore little resemblance to the real Cavaliers.

LeBron James and J.R. Smith watched from the bench. Kevin Love and Kyrie Irving didn’t even get that far. None of those four starters played because Cleveland already had clinched the No. 2 playoff berth in the Eastern Conference.

Still, Stevens was impressed with the 117-78 victory Sunday that reduced to one Boston’s magic number for a postseason spot that seemed so unlikely not long ago.

“Our guys just played very maturely the whole game,” he said. “I thought we played well, but, obviously, they didn’t play their best players.”

The Celtics would clinch a playoff spot if Indiana loses to Oklahoma City on Sunday night.

Cavaliers coach David Blatt wasn’t concerned that his decision to rest four starters could hurt the Pacers’ postseason prospects. He plans to use all four Monday night against Detroit.

“Indiana wasn’t upset when they played us and we had to sit a player or two,” he said. “We played Indiana in Indiana and we sat LeBron because it was tough back-to-back (games) after (a) plane failure and we flew in the day of the game.

“That didn’t bother them then. I don’t see what would bother them now. That’s the nature of the league.”

If the Celtics remain in seventh place in the East, they would face the Cavaliers in the first round.

“We’ll be ready if we play them,” said Iman Shumpert, who led Cleveland with 15 points and 10 rebounds but had seven turnovers.

Isaiah Thomas led seven Celtics in double figures with 17 points. Evan Turner added 15 and Avery Bradley had 12. The Celtics had 20 steals, high in an NBA game this season and one less than their franchise record.

The playoffs seemed extremely unlikely for the rebuilding Celtics when they were 16-20. But they are 22-12 since then after settling on a starting lineup and regular rotation after numerous personnel moves.

“We didn’t even know we had a chance back in the beginning of January,” Tyler Zeller said. “It says a lot about the group we have just coming out every night and competing.”

The Celtics outscored the Cavaliers 34-9 in the second quarter to take a 55-31 lead and stayed ahead by 20 to 41 points the rest of the way.

Boston won by its biggest margin of the season while Cleveland had its worst loss.

The win was the Celtics’ fourth straight and followed a 99-90 victory on Friday night that ended the Cavaliers’ 18-game home winning streak. Irving missed that game with a sore hip and James and Love did not play in the fourth quarter as Blatt decided to rest them.

On Sunday, Boston took advantage of Cleveland’s sloppy play and poor shooting. In the first half, the Cavaliers committed 12 turnovers (10 steals), and made only 29 percent of their shots (12 of 42).

The Celtics scored the first nine points of the game, but the Cavaliers tied it by getting the next nine.

With the game tied at 24, Boston pulled away again and this time Cleveland couldn’t catch up. The Celtics scored the next 12 points and extended the run to 23-3 to take a 47-27 lead with 4 minutes left in the second quarter.

With the score 67-47, Bradley hit an 18-footer to start a 15-3 run that put the Celtics on top 82-50 as Thomas ended it with a 3-pointer.

STOP, THIEF: Turner and Marcus Smart led Boston with four steals each and Jae Crowder had three. Shawn Marion had Cleveland’s only steal. “Marcus Smart was phenomenal today on the ball,” Stevens said. “He just made every pass really difficult from the point.”

HIGHS AND LOWS: Boston’s 117 points were tied for its fifth-most this season. Cleveland’s 78 matched its season low.

TIP-INS: Cavaliers: Shumpert made his first start for Cleveland in 36 games since being obtained from New York. … Cleveland’s previous worst loss of the season was by 29 points, 127-98 to Atlanta on Dec. 17. James had 21 points, Love had 10 rebounds and Irving had six assists in that game. Celtics: Boston had 29 assists to 18 for the Cavaliers. The Celtics committed just nine turnovers to 25 for the Cavaliers. … The Celtics’ previous biggest win of the season was by 22 points, 106-84 against Sacramento on Dec. 31.