SAN FRANCISCO (AP) — Bruce Bochy just went for it and pegged Joe Panik as a 60-home run guy. Joking of course, but the second baseman is on quite a pace.

His latest solo home run wasn't enough against Seattle.

Mitch Haniger hit a two-run single, Kyle Seager also singled in a run in a big first inning, and the Mariners spoiled the Giants' home opener with a 6-4 win Tuesday.

Panik went deep in the fourth, his third solo drive of the season. At that point, he had accounted for all three of San Francisco's runs for the season with those shots.

At this rate, the Giants might need him to hit 60 just to stay competitive.

"All I can do is laugh about that one," Panik said of Bochy's bold prediction.

Marco Gonzales (1-0) allowed three runs and six hits in 6 1/3 innings for the Mariners.

Evan Longoria added a two-run shot for the Giants, the first hit with his new team after an 0-for-17 start.

Behind Panik's power bat, San Francisco became the first team in major league history to score its first three runs of the year on solo homers by the same player, according to Elias. It was Panik's first homer at AT&T Park since Aug. 28, 2016 — all 10 of his came on the road in 2017.

The Mariners answered right back in the fifth, getting Robinson Cano's RBI double and a sacrifice fly from Guillermo Heredia.

"The credit goes to our offense today," Gonzales said. "The four runs in the first, couldn't ask for a bigger boost of confidence honestly, and the way they played in the field it was a huge team win all the way around."

Austin Jackson added a sacrifice fly in his home debut for the Giants, while new right fielder Andrew McCutchen made a snazzy diving catch in the ninth.

Ty Blach (1-1), filling in for injured ace Madison Bumgarner, was done after 4 1/3 innings having allowed 10 hits and six runs. He tossed five innings in a season-opening 1-0 win at Dodger Stadium last Thursday.

Seattle jumped on the lefty immediately, the first three batters reaching base without the ball leaving the infield: An infield single by Dee Gordon, bunt base hit for Jean Segura and a walk to Robinson Cano before Haniger delivered.

Edwin Diaz finished for his third save.

The Giants had been 1 for 28 with runners in scoring position in their season-opening split of a four-game road series against the Dodgers. San Francisco's two runs in the initial four contests were its fewest in franchise history.

"We haven't clicked yet, but we will," Bochy said.

The crowd of 40,901 marked the lowest for a Giants home opener in the 19-year ballpark's history.

Ex-San Francisco closer Brian Wilson threw out the ceremonial first pitch.

The club remembered the late San Francisco Mayor Edwin Lee, who died suddenly in December.

BAKER IS BACK

Dusty Baker, back with the Giants in an advisory role after last managing the team to the 2002 World Series, walked onto the field and shared a warm embrace with CEO Larry Baer before making the rounds behind the dugout and hugging. Baker was fired as Washington's manager this offseason.

"I'm liking it but it's a little strange," Baker said of the new gig. "I didn't think I'd have another opener. On the whole, things worked out. Here I am with opening with the Giants seeing a lot of old friends, even old friends on the other team, like (Seattle manager) Scott Servais played for me here with the Giants."

ICHIRO'S RETURN

Ichiro Suzuki laughed and smiled when his inside-the-park All-Star Game homer at AT&T Park in 2007 was brought up to him before the game.

"That was a long time ago," Suzuki said.

This marked his first regular-season game in San Francisco with the Mariners, as his last time still with Seattle was in the All-Star Game.

TRAINER'S ROOM

Mariners: Seattle placed DH Nelson Cruz on the 10-day disabled list after he suffered a sprained right ankle slipping on the dugout steps following a two-run homer Saturday against Cleveland. "I'm very optimistic and hopeful that he'll be back at the end of the 10 days," manager Servais said. Cruz will rehab in Seattle and not travel with the team. ... C Mike Zunino (strained left oblique) could join the Mariners on the road trip as he's eligible to be activated Friday. ... RHP Erasmo Ramirez (strained right lat muscle) was scheduled to pitch a simulated game of about 30 pitches for Triple-A Tacoma on Tuesday while OF Ben Gamel (strained right oblique) is set to play for the Rainiers on Thursday and could be ready after the road trip.

Giants: C Nick Hundley started as Bochy moved Buster Posey to play first. ... RHP Jeff Samardzija, sidelined by a right pectoral strain, threw a 30-pitch bullpen session and is expected to do another hard throwing day before beginning a rehab assignment.

UP NEXT

Felix Hernandez pitches for Seattle going for his second victory in the finale of the two-game interleague set as the Giants send right-hander Johnny Cueto (0-0) to the mound.