PEORIA, Ariz. -- Jason Bay bolstered his hopes of making Seattle's Opening Day roster with a two-run home run in the first inning on Saturday as the Mariners topped the Padres, 8-6, at the Peoria Sports Complex.

Bay, who signed a one-year, $1 million deal in December, jumped on a 1-0 pitch, sending it over the fence in left field. Bay also reached base twice on walks.

"That's probably the last thing you think about," Bay said of hitting a home run. "I'm just trying to go up there and get some timing. Whether it's Spring Training or not, you want to just relax and kind of go from there."

Bay wasn't the only Mariner to go deep, as Justin Smoak drilled a two-run home run in the fifth inning. Smoak's home run came off Padres reliever Brad Boxberger.

Seattle starting pitcher Blake Beavan (1-0) allowed two hits in two scoreless innings. He struck out one and didn't walk a batter. Beavan, who was 11-11 with a 4.43 ERA last season, is competing for the fourth or fifth spots in the starting rotation.

San Diego starting pitcher Tyson Ross, trying to win a job in the starting rotation, allowed the home run to Bay and then a hit in his second inning of work. All told, Ross (0-1) yielded two runs on three hits with one walk and two strikeouts in two innings.

Ross was obtained in November from the A's for pitcher Andrew Werner and infielder Andy Parrino. His younger brother, Joe, is considered one of the top pitching prospects in the Padres' system.

"I thought he threw the ball fine, I thought his arm strength and velocity looked good and he threw a couple of good changeups, which he needs to do," said Padres manager Bud Black of Ross.

San Diego's Wilfredo Boscan, who is in camp as a non-roster invitee, struck out one and also walked one in two innings of scoreless relief.

Two of the top pitching prospects in the game, Seattle's Taijuan Walker and Danny Hultzen, appeared in the game. Walker allowed one hit in one scoreless inning. Hultzen worked a 1-2-3 fifth inning.

The Padres got on the scoreboard in the sixth inning when, after Jesus Guzman walked, Jeudy Valdez doubled in a run to make it 4-1. Valdez later hit a two-run homer in the ninth and Jedd Gyorko added two more with a single.

Mike Jacobs slugged Seattle's third two-run homer of the day in the ninth.

Padres up next: Veteran Freddy Garcia, who signed a Minor League contract last month, is scheduled to throw two innings against the Mariners at 12:05 p.m. PT. Garcia is one of a handful of pitchers in camp trying to win a job in the starting rotation. He has the most experience of any of them, as the 36-year-old has won 152 games over his 14-year career. The Padres will also get their first look at two promising Minor League pitchers, Johnny Barbato and Matt Stites. Both are in their first big league camp and will begin the season in the Minor Leagues.