Rajai Davis tripled in the go-ahead run as the host Oakland Athletics defeated longtime nemesis John Lackey and the Boston Red Sox 4-3 on Saturday night.

Davis tripled to deep center field to drive in Mark Ellis to cap a three-run seventh inning as the Athletics beat Lackey for only the fifth time in the pitcher’s 22 career decisions against the franchise.

Daric Barton led off the seventh with a double and scored on Jack Cust’s one-out, run-scoring single. Cust moved to second on left fielder Billy Hall’s error and scored on Mark Ellis’ single to center.

One out later, Davis delivered the go-ahead hit that helped Oakland win its second straight game in the series.

Oakland starter Brett Anderson (5-6) gave up two runs and eight hits in seven innings. Anderson struck out five.

Craig Breslow pitched a perfect eighth and Andrew Bailey closed it out for his 23rd save by striking out David Ortiz. Boston scored a run in the ninth on back-to-back two-out doubles by Victor Martinez and Adrian Beltre.

Cust singled in an important insurance run in the eighth for Oakland.

Boston’s runs scored on Mario Scutaro’s third-inning homer and Ryan Kalish’s run-scoring single in the sixth.

Lackey (12-10) gave up three runs and six hits in seven innings.