PEORIA, Ariz. -- Right fielder Justin Maxwell -- who hit a three-run homer in the fourth -- keyed the Giants' five-run rally in the ninth to edge the Mariners, 9-8, in Cactus League action at Peoria Stadium on Saturday.
Mariners catcher Mike Zunino cracked a pair of solo home runs, and third baseman Kyle Seager added another on a mid-90-degree day where the ball was flying.
Zunino led off the second with his team-leading fifth homer of the spring, a shot to left field off Jake Peavy to give Seattle a 3-1 lead. Zunino added his second blast in the sixth off Jeremy Affeldt. The 24-year-old went 2-for-3 on the day to raise his spring average to .310 in 16 games.
"I was just looking for pitches early in the count to drive," said Zunino. "I'm feeling all right. Just continuing to try to make adjustments and seeing a little bit of improvement. It's something to keep building on."
Peavy, making his fifth start of the spring, gave up seven hits and six runs (five earned) with one walk and one strikeout as his ERA rose to 8.22 in 15 1/3 innings.
Hisashi Iwakuma, in his second-to-last start of the spring for Seattle, went five innings and allowed four runs on five hits with two walks and four strikeouts on 85 pitches.
"I felt pretty good," Iwakuma said through interpreter Antony Suzuki. "I feel like I can enter the season right now physically. From here on, it's all mental. I feel like I have a lot of life on my fastball, and that's a good sign."
Iwakuma came into the game yet to allow a run in six Cactus League innings, but Giants leadoff man Gregor Blanco opened with a triple down the right-field line and scored on a fielder's choice grounder by Travis Ishikawa. Blanco went 2-for-3 on the day to raise his spring average to .326.
Seattle answered with two runs in the bottom of the first when Seth Smith scored from first on Robinson Cano's double, which glanced off the glove of left fielder Juan Perez. That error allowed Cano to take third, and he scored from there on Nelson Cruz's sacrifice fly.
Maxwell, competing for a backup-outfielder job as a non-roster invitee, hit his second homer of the spring with his bolt off Iwakuma after Ishikawa walked and Casey McGehee singled leading off the fourth.
"That was a slider I kind of got under," Iwakuma said. "It was up in the zone. It was a pitch I missed with."
Seager re-tied the game at 4 with his leadoff shot in the bottom of that frame, his third Cactus League homer coming on the first pitch of the inning. Willie Bloomquist and Justin Ruggiano gave Seattle a 6-4 advantage with one-out RBI singles before Peavy's day was done after 83 pitches.
Bloomquist added an RBI double in the sixth in a 2-for-3 day with two RBIs.
After Maxwell singled to lead off the ninth, the Giants tallied on Brett Jackson's double, Pedro Ciriaco's single, Kelby Tomlinson's triple and a wild pitch from right-hander Mark Lowe.
Up next: Left-hander J.A. Happ gets the start as Seattle plays a "road game" against the Padres at Peoria Stadium. Happ has a 7.27 Cactus League ERA after giving up eight hits and five earned runs in 3 2/3 innings in his last outing against these same Padres. He will look to get squared away in his second-to-last spring start in a 1:05 p.m. PT game that will broadcast live on ROOT Sports and MLB.TV.