BOSTON – Jon Lester isn't about to make any drastic changes following his shortest outing this season.
Boston's ace left-hander knows precisely what went wrong.
Lester lasted only 4 1-3 innings Friday night, surrendering six runs on a season-high 11 hits as the Red Sox had their three-game winning streak snapped with a 7-6 loss to the Arizona Diamondbacks.
"It's not like I need to reinvent any type of wheel or come out and start throwing right-handed or anything," Lester said. "It's pretty simple — get the ball down. I do that, it's a different story tonight."
Coming off back-to-back walk-off wins, including Thursday night when they charged back from six runs down in the ninth to edge Seattle, Boston maintained its one-game lead over Tampa Bay for first place in the AL East. The Rays lost 4-1 to San Francisco.
It was a bit of deja vu for the Red Sox on Friday, when Brad Ziegler allowed ninth-inning singles to Stephen Drew and Jacoby Ellsbury but got his sixth save by retiring the last two batters.
"Things started to build, a little momentum, similar to the feeling that we've had the last couple of nights," Boston manager John Farrell said. "But unfortunately it didn't happen here tonight."
Lester struck out six without walking a batter, but struggled from the onset, yielding a two-run home run to Paul Goldschmidt just three batters into the game.
With Clay Buchholz (9-0, 1.71 ERA) sidelined since his last start June 8 with neck and shoulder ailments, Lester once again is considered Boston's ace — and he's pitched the part his last few times out.
Lester owned a 2.29 ERA over his last three starts, including seven innings of shutout ball against Baltimore on Sunday, and had won four of his last seven starts.
But leaving the ball up in the zone and over the plate cost him five doubles and a homer against Arizona.
"I'll take my beatings if they find holes in the infield. I'll tip my hat all day to that," Lester said. "But when you're giving up doubles in the gap and balls of the wall, misfired fastballs, it's just unacceptable."
Cody Ross capped his four-hit return to Fenway Park with a tie-breaking homer that helped the Diamondbacks win for just the second time in their last six games.
Ross, Boston's regular right fielder last season, drove in three runs, doubled twice and singled once. His big hit came with the score tied at 6 when he led off the seventh inning against Pedro Beato (1-1) with his seventh homer of the year.
In his only season with the Red Sox, Ross hit .267 with 22 homers and 81 RBIs last year. But they let him leave as a free agent and signed Shane Victorino to take his spot in right.
"Obviously," Lester said, "he came back with a little bit of a chip on his shoulder."
Ross doubled in the first on Friday then singled in a run in the third, cutting Boston's lead to 4-3. He hit another RBI double in the three-run fifth when Arizona went ahead 6-4. He finished his night by grounding out in the ninth.
The Red Sox had tied the game 6-6 in the sixth on Drew's two-run homer, his eighth of the year, after a single by Mike Napoli.
Randall Delgado (4-3) got the win despite his worst performance of the season. He gave up six runs in six innings, the first time in his nine starts this year that he allowed more than three. But he got out of trouble in the third when the Red Sox loaded the bases with one out but didn't score.
Goldschmidt gave Arizona a 2-0 lead with his 25th homer after a single by Aaron Hill. Boston tied it in the bottom of the inning when Ellsbury tripled and scored on David Ortiz's 21st homer.
The Red Sox made it 4-2 in the second when Daniel Nava reached on a throwing error by shortstop Didi Gregorius, Jarrod Saltalamacchia doubled him to third and Drew and Brock Holt hit sacrifice flies.
The Diamondbacks took a 6-4 lead with three runs in the sixth on RBI doubles by Prado and Ross and a run-scoring single by Jason Kubel.
NOTES: Jack Peavy (8-4) makes his first start for Boston since being obtained from the Chicago White Sox when he faces Patrick Corbin (12-2) on Saturday night. ... Ortiz has reached base in 16 straight games. ... Arizona SS Gregorius struck out in all four at bats. ... J.J. Putz pitched 2-3 of an inning in relief of Delgado and held the Red Sox scoreless for the 13th straight game, starting in Aug. 26, 2006. ... Lester didn't issue a walk for the second time in three games.