SEATTLE — Felix Hernandez was anxious for his opportunity to be back on the mound pitching for Seattle for the first time in nearly two months. It helped the Mariners’ offense made sure Hernandez didn’t need to worry about being perfect. Hernandez pitched six solid innings in his first start since late April and was backed by home runs from Mike Zunino, Ben Gamel and Kyle Seager in the Mariners’ 13-3 win over the Houston Astros on Friday night. A day after climbing over .500 for the first time this season, the Mariners continued their June surge with their sixth straight win thanks to an offense that knocked out Houston starter Joe Musgrove (4-7) early and got a strong performance from Hernandez. “This lineup is a little scary,” Hernandez said. Jarrod Dyson’s RBI double in the second got Seattle started, but it was a six-run third inning that blew the game open.