Jaylen Brown scored 19 points and Marcus Morris led a strong bench effort with 18 points as the Boston Celtics handed the host Detroit Pistons their first loss with an easy 109-89 victory on Saturday night.Boston controlled the game virtually from the opening tap and led by 22 at halftime. Daniel Theis had 17 points and eight rebounds, Gordon Hayward supplied 15 points and Terry Rozier added 14.Pistons forward Blake Griffin, who entered the game averaging 33.8 points, was held to seven points on 2 of 13 shooting from the field.Andre Drummond led Detroit with 18 points and eight rebounds while Stanley Johnson contributed a season-high 16 points.Boston shot 45.3 percent from the field and held Detroit to 37.1 percent shooting. The Pistons made just seven of 37 attempts from beyond the arc. Boston posted a 62-34 edge in bench scoring.The Celtics received 34 points from their reserves in the first half and built a 63-41 halftime lead. Theis led the way with 14 points and seven rebounds while former Piston Morris tossed in 11 points.Griffin shot just 1-for-9 from the field before the break as Johnson was the only player to reach double figures for Detroit. But his 13 points couldn’t keep the PIstons close as Boston shot 50 percent overall before intermission and 56.3 percent from long range.Boston led by double digits for the last 11 minutes of the half. A Rozier 3-pointer finished off an 8-0 spurt to make it 40-23.