(Photo credit: Joe Nicholson-Imagn Images)

Leo Rivas hit a two-run homer leading off the bottom of the 13th inning as the Seattle Mariners defeated the visiting St. Louis Cardinals 4-2 on Wednesday to keep pace in the American League playoff race.

Rivas, who entered the game as a pinch runner in the 11th, lined the first pitch of the 13th from St. Louis' Ryan Fernandez (0-3) just inside the right field foul pole to also score Josh Naylor, who started the inning as the runner at second base.

Emerson Hancock (4-5) pitched two scoreless innings of relief for the victory.

The Mariners (78-68) won their fifth in a row. They remained one game behind the first-place Houston Astros in the AL West and 1 1/2 games ahead of the Texas Rangers in the chase for the third AL wild card.

Ivan Herrera hit a solo homer for the Cardinals (72-75), who lost their third in a row.

Both teams scored in the 11th inning. Thomas Saggese, who went 4-for-5, grounded a single up the middle against a drawn-in infield to give the Cardinals the lead. Seattle's Jorge Polanco led off the bottom of the inning with a run-scoring double to tie it.

Cardinals reliever Riley O'Brien, a Seattle native, allowed one unearned run over two innings but escaped bases-loaded jams in the 10th and 11th to keep the game going.

Herrera homered with one out in the first inning, hammering a hanging breaking pitch from Logan Gilbert 411 feet into the back of the Mariners' bullpen beyond left-center field.

Gilbert was the victim of a rising pitch count and lasted just 4 2/3 innings. The right-hander gave up one run on five hits with one walk and eight strikeouts.

The Mariners tied it in the second. Naylor and Polanco opened the frame with singles and advanced on a groundout to the right side of the infield by Eugenio Suarez. Naylor scored on Dominic Canzone's sacrifice fly to left.

Cardinals starter Michael McGreevy pitched six innings and allowed one run on five hits. The rookie right-hander didn't walk a batter and fanned four.

--Field Level Media