Pedro Pages hit a decisive two-run homer in the bottom of the eighth inning as the host St. Louis Cardinals beat the Seattle Mariners 2-0 in a pitchers’ duel on Saturday night.

Pages sent a ball over the left-center-field wall after Jordan Walker was hit by a pitch with one out in the eighth. It was Pages’ sixth homer of the year.

Cardinals starter Kyle Gibson blanked the Mariners for 6 2/3 innings, giving up three hits and walking three. Gibson fanned nine while recording his 1,500th career strikeout.

Relievers JoJo Romero, Andrew Kittredge and Ryan Helsley completed the shutout for the Cardinals (72-70). Kittredge (4-4) earned the victory, and Helsley got his 43rd save of the season.

St. Louis won for the seventh time in 10 games while the Mariners (72-71) saw their three-game winning streak end.

Seattle starter Logan Gilbert (7-11) allowed two runs on two hits in eight innings. He struck out 10 and walked one.

Julio Rodriguez and Cal Raleigh opened the game with singles and Luke Raley drew a one-out walk for the Mariners. But Gibson struck out the next two batters to leave the bases loaded.

Randy Arozarena hit a two-out double in the third inning, but Gibson got Raley to ground out to end the frame.

Gilbert retired the first 10 batters he faced before walking Alec Burleson with one out in the fourth inning. However, he kept the game rolling by getting Paul Goldschmidt to ground into a double play.

Lars Nootbaar got the Cardinals’ first hit, a one-out double in the fifth inning. Gilbert responded by striking out Walker and Pages.

Gibson retired 11 straight batters before walking Jorge Polanco with one out in the seventh inning. Mitch Haniger drew a two-out walk, then pinch hitter Dylan Moore drew a walk while facing Romero.

But Rodriguez grounded out as Seattle left the bases loaded again.

Raleigh led off the eighth inning with a single off Kittredge. Arozarena hit into a forceout, but he later ended up moving to second on Kittredge’s errant pickoff throw.

After Justin Turner drew a two-out walk, Polanco flied out to strand the runners.