Royals 5, Red Sox 1: Bruce Chen tossed 7 2/3 scoreless innings and Mike Moustakas ripped a two-run single as host Kansas City recorded its 14th victory in 16 outings.

Billy Butler and Justin Maxwell provided insurance with solo homers in the eighth inning for the Royals, who improved to 16-4 since the All-Star break. Kansas City moved within 4 1/2 games of idle Oakland and Texas for the second wild card in the American League.

Stephen Drew had a single in the sixth inning to extend his season-high hitting streak to nine games. He added an RBI single in the ninth for the Red Sox, who fell for the third time in nine contests to see their lead in the American League East dip to two games over second-place Tampa Bay.

Chen (5-0) yielded five hits - all singles - and struck out a pair before departing to a nice ovation in the eighth inning. Luke Hochevar came on with two runners aboard and induced Shane Victorino to pop out harmlessly to end the threat before notching his second save.

Kansas City jumped on Jon Lester (10-7) right from the start as it taxed him for 41 pitches in the first inning. Alex Gordon gave the Royals a 1-0 lead after his fly ball was misplayed by left fielder Jonny Gomes, allowing Lorenzo Cain to score. Moustakos then ripped a 2-2 fastball into right field to plate Butler and Gordon.

GAME NOTEBOOK: Lester fell to 6-3 against the Royals after permitting three runs on four hits in seven innings. ... Kansas City SS Alcides Escobar successfully stole his 13th base in as many chances during the seventh inning. ... Red Sox 1B Daniel Nava returned from paternity leave and went 1-for-3.