KANSAS CITY, Mo. (AP) — Bruce Chen outdueled Jon Lester as the Kansas City Royals defeated the Boston Red Sox 5-1 on Thursday night.

The Royals won for the 16th time in 20 games since the All-Star break. The Red Sox, who have the best record in the American League, lost for only the third time in 10 games.

Chen (5-0), who was making his fifth start since beginning the season in the bullpen, did not allow a runner past first base until the eighth and retired 11 in a row in one stretch. He yielded five singles, walked one and struck out two.

Lester (10-7), who came into the game with a 6-2 record and a 1.64 ERA in nine starts against the Royals, needed 41 pitches in the first inning when Kansas City sent eight men to the plate and scored three runs.