HOUSTON -- This is all that had to happen before Justin Turner became the Mets' everyday second baseman:
Luis Castillo had to get released during spring training.
Opening Day second baseman Brad Emaus had to get designated for assignment after batting .162 in 37 at-bats.
Turner, starting his fourth straight game, hit a three-run homer and two-run double Sunday as the Mets beat the Astros, 7-4, at Minute Maid Park to win their third straight series.
Turner's blast to leftfield off Aneury Rodriguez in the sixth inning was the former Oriole's first big-league home run.
"He had a good day," manager Terry Collins said. "He likes to play. This is his chance. You spend quite a few days in the minor leagues and you sit there and say, 'If I just had a chance.' This is his opportunity and he's making the most of it."
Turner, 26, who is batting .308 with nine RBIs, is 5-for-9 with runners in scoring position since joining the Mets on April 19, when they ended their Emaus infatuation. He's 5-for-16 (.313) since Davis got hurt Tuesday.
"It's nice to come to the field every day knowing you're in the lineup," Turner said. "It's an opportunity and I'm just trying to take good at-bats. If I get a hit out of it, it's just a little bonus. It felt pretty good today, obviously."
The Mets claimed Turner off waivers from Baltimore last May 25. He appeared in four games in July before returning to Triple-A Buffalo. His career major-league average entering this season was .114 (4-for-35).
Still, Collins and bench coach Ken Oberkfell -- last year's manager at Buffalo -- saw something in the redhead from Long Beach, Calif. Turner was a contender for the second-base job in spring training but started the season at Buffalo.
"He's a baseball player," Collins said. "I saw him last year. We just felt it was important to give Brad Emaus a chance. So Justin had to go down and get some at-bats and play and we had to make a decision on Brad. Nobody's a better rooter of Justin Turner's than Ken Oberkfell. He saw him every day, and there's something to be said for that."
Rodriguez (0-2) held the Mets hitless for four innings before they exploded for four runs in the fifth to erase a 2-0 deficit.
After Murphy singled, Turner failed on a sacrifice bunt attempt before rapping his two-run double down the third-base line, one of only five Mets hits. Jason Pridie put the Mets ahead with an RBI single to center.
Four batters later, Pridie headed home when he saw second baseman Bill Hall turn his back to the plate after a halfhearted attempt to tag Jose Reyes on a steal. Pridie scored without a throw on the double steal.
Notes & quotes:Carlos Beltran (0-for-4) returned to the lineup after sitting Saturday with a swollen eye . . . When asked about the Jorge Posada situation, Collins joked about posting a lineup with Reyes batting ninth to "see what the response was." But he thought better of tweaking the Mets' crosstown rivals. "I probably don't want to touch that,'' he said, "since we're playing them this week."