Randy Arozarena and Jorge Polanco hit two-run home runs to power the visiting Seattle Mariners past the St. Louis Cardinals 10-4 Sunday.

Luke Raley and Mitch Garver drove in two runs apiece, and Raley, Arozarena, Julio Rodriguez and Justin Turner scored twice for the Mariners (73-71), who won for the fourth time in five games.

Seattle’s victory came at a cost. Starting pitcher Luis Castillo exited the game with a left hamstring strain in the fourth inning.

Castillo allowed two runs on five hits while retiring nine batters before his departure. Reliever Trent Thornton (4-3) tagged in and pitched two scoreless innings to earn the victory.

Jose Fermin and Jordan Walker drove in two runs apiece for the Cardinals (72-71), who dropped two of three games to the Mariners to suffer their first series loss since Aug. 16-18 against the Los Angeles Dodgers.

The Mariners pounded Cardinals starting pitcher Miles Mikolas (8-11) for seven runs (six earned) on nine hits in two innings. Mikolas struck out three and walked none.

After getting shut out Saturday, Seattle rebounded to score five runs in the first inning.

Rodriguez led off the game with a double and scored on Cal Raleigh’s single. After Arozarena hit a single, Raley delivered a two-run double.

Turner hit a single, and two outs and one passed ball later, Garver’s two-run single made it 5-0.

The Mariners increased their lead to 7-0 in the second inning on a single by Rodriguez and Arozarena’s 19th homer of the year.

The Cardinals got two runs back in the second inning. Nolan Arenado hit a leadoff single, Ivan Herrera hit a one-out double and Fermin drove them home with a two-out single.

But Seattle made it 9-2 in the fifth inning when Turner walked and Polanco hit his 14th home run.

St. Louis cut its deficit to 9-4 in the eighth inning when Matt Carpenter hit a double, Lars Nootbaar walked and Walker hit a two-run double.

Seattle added a run in the ninth inning on doubles by Raley and J.P. Crawford.