KANSAS CITY, Mo. (AP) — Justin Maxwell homered and singled twice in a six-run sixth as the Kansas City Royals rallied for a 9-6 victory over the Boston Red Sox on Friday night.

The Royals have won 15 of their past 17 games to move seven games above .500, matching their best record of the season.

Maxwell, who the Royals acquired on July 31 from the Houston Astros for a minor league pitcher, homered leading off the second.

With the Royals trailing 6-3 in the sixth, he led off the inning with a single. The Royals sent 11 men to the plate in the inning against Red Sox pitchers Jake Peavy, Drake Britton and Pedro Beato.

Peavy, who was making his second Red Sox start since being acquired in a July 30 trade from the Chicago White Sox, yielded singles to Maxwell, Mike Moustakas and Alcides Escobar to start the inning. Escobar’s RBI single finished Peavy.

Eric Hosmer’s two-run single with two outs off Britton put the Royals on top 7-6. David Lough contributed a sacrifice fly, while Billy Butler doubled home Hosmer. Maxwell’s second single in the inning scored Butler with the final run.

Mike Napoli, a career .368 hitter off Royals right-hander Ervin Santana, cleared the bases with a two-out third inning three-run double.

That ended Santana’s night. He gave up six runs on nine hits, including David Ortiz’s 22nd home run in the third, in 3 2/3 innings, his shortest outing of the season.

Peavy lasted five innings, plus three batters, allowing six runs on 10 hits.

Francisley Bueno (1-0), who was just promoted Thursday from Triple-A Omaha, picked up the victory with 2 1-3 scoreless innings. He has two big league wins, both against the Red Sox. Britton (1-1) was charged with the loss.

The Royals’ 16-hit attack, included three hits each by Butler, Hosmer and Maxwell. Alex Gordon had two hits, including his 12th home run.

Greg Holland worked the ninth for his 31st save in 33 chances.

Notes: Red Sox C David Ross, who has been out since June 18 with a concussion, could start rehabbing with Tuesday with Double-A Portland if he gets the final approval. He has been cleared by Dr. Michael Collins, a concussion specialist in Pittsburgh, and the results were forwarded to Major League Baseball, which has the final word. If all goes well, Ross could be activated Aug. 19, the first day he is eligible. … Royals All-Star C Salvador Perez is progressing in his on-the-field activities and manager Ned Yost is hopeful he’ll get the clearance to play Sunday, the first day he is eligible. … After an appeal from the Royals, MLB reversed two Mets scorings calls from Sunday, giving Alex Gordon and Lorenzo Cain hits on “sun balls” that were first called errors.