Gavin Sheets hit two home runs and Lucas Giolito combined with two relievers on a one-hitter in his San Diego debut as the Padres defeated the host Seattle Mariners 8-3 on Sunday, sweeping the six-game Vedder Cup series this season.

Mariners top prospect Colt Emerson was called up from Triple-A Tacoma earlier in the day when Brendan Donovan (strained left groin) went on the 10-day injured list. Emerson played third base and batted ninth, going 0-for-2 with a walk and scoring a run in his major league debut.

Seattle's only hit was Luke Raley's one-out grounder into right field for a single in the second inning.

Giolito, signed as a free agent by the Padres on April 22, allowed one hit and no runs through the first five innings. He had an extended stretch on the bench as San Diego scored five times in the top of the sixth to take a 7-0 lead.

By the time Giolito returned to the mound, he lost his command, walking the first three batters in the bottom of the inning. Left-hander Yuki Matsui replaced Giolito and walked Josh Naylor with the bases loaded before Randy Arozarena and pinch hitter Rob Refsnyder added sacrifice flies to pull the Mariners within 7-3.

Giolito (1-0) was charged with three runs on one hit in five-plus innings. The right-hander walked three and struck out three.

Matsui and Bradgley Rodriguez both pitched two hitless innings of relief.

Sheets hit a solo homer in the first inning and a two-run shot in the sixth, both to right off George Kirby (5-3), and added a run-scoring double in the seventh.

The Padres made it 2-0 in the fifth as Xander Bogaerts drew a leadoff walk, stole second and third and scored on former Mariner Ty France's two-out single to right.

San Diego pulled away in the sixth as, with one out, Miguel Andujar doubled, Sheets homered and Manny Machado doubled. An out later, Jackson Merrill doubled to make it 5-0 and chase Kirby.

Reliever Cooper Criswell walked Ramon Laureano and threw a wild pitch, advancing the runners to second and third. France lined a two-run single to center for a 7-0 advantage.

Kirby allowed six runs on six hits over 5 2/3 innings. The right-hander walked two and struck out six. Kirby dropped to 0-3 in three career starts against San Diego with a 10.05 ERA.

Mariners shortstop J.P. Crawford left after four innings after being hit by a Giolito pitch in his right triceps.