Celtics’ win easy as 1-2-3

In order to make everything run smoothly and snap a three-game losing streak, Celtics coach Doc Rivers came up with one mantra: Simplify everything. And in every timeout during the Celtics’ 103-96 win over the Raptors at TD Garden last night, everyone from Rivers down to each of his assistants repeated the refrain.

“We kept it simple,’’ Rivers said. “We had a theme going into the game. Fortunately it was the right theme, because sometimes you just don’t know. But every single guy, you could hear the whole time repeating it over and over again.’’

The blueprint was the same - defense first, unselfishness second. The steps were just easier to follow.

“We didn’t do anything different really,’’ Rivers said. “We just ran our stuff. We simplified it because we thought we had to.’’

The Celtics shot 51.4 percent from the floor, they won the rebound battle, 36-28, and with 26 assists on 36 field goals, they kept the ball moving on offense. For Rivers, figuring out a way to win, was like piecing together a puzzle, but the key was making sure each player knew which piece it was.

Rivers didn’t expect Tony Allen to be Rajon Rondo (hamstring strain). He knew that with just weeks on the floor, Allen only knew a handful of plays. So, in Thursday’s practice, Rivers only put in four plays, and emphasized more passing and less dribbling. And when the situation called for more plays, then so did Rivers.

“In some ways, I never called more plays probably in my life,’’ Rivers said. “But we knew that coming in.’’

Allen finished with 14 points and seven assists. He was one of four players in the Celtics piece-meal starting five to finish in double figures. Ray Allen, playing with a bull’s-eye as the Celtics’ primary scoring option, put up a team-high 23 points on 8 of 13 shooting. Kendrick Perkins finished with 14 points and 10 rebounds. Rasheed Wallace scored 16, buoyed by a 12-point first half.

Giddens was 1 for 3 in his first career start, but Rivers never expected him to transform into Paul Pierce (knee infection). He wanted him to be effective.

“All we tried to do was keep them in positions where they couldn’t fail,’’ Rivers said. “We tried to get them out of harm’s way I guess.’’