PORT ST. LUCIE — David Wright hit a grand slam and Mike Pelfrey had his best outing of the spring as the Mets beat the Houston Astros 9-1 Thursday night.

Wright drove a full-count breaking ball from Livan Hernandez over the left field fence to cap a seven-run fourth inning for the Mets. It was the first home run of the spring for the veteran third baseman, who missed all but three games while recovering from a torn rib cage muscle.

Pelfrey came into the game with a 11.49 ERA, but gave up just one run on three hits in 6 1-3 innings. He also struck out three and didn’t walk anyone.

Hernandez lasted just 3 2-3 innings. He allowed eight runs — four earned — and seven hits.