Dillon Gee finished the spring with two earned runs allowed in 20 2/3 innings pitched. (AP)

KISSIMMEE, Fla. -- Mets right-hander Dillon Gee pitched six innings of no-hit ball, walking just one batter while striking out seven before the Astros came to life in the seventh inning of a 9-6 Houston win over the Mets on Wednesday night at Osceola County Stadium.

Gee, who will start on Opening Day for the Mets, will become the 23rd different pitcher to start the Mets' first game of the season when he gets the ball Monday. He allowed only two earned runs this spring in 20 2/3 innings.

"Outside of one base on balls, he was about as on -- location-wise and stuff-wise -- as you'd want to see," Mets manager Terry Collins said. "He's ready to go. He's ready to open up. He's excited about it, and tonight he showed it. He's really working to get himself ready."

"I felt really good out there," Gee said. "The key is fastball command, and tonight I felt pretty sharp. I felt I was throwing the fastball where I wanted to. ... I was aggressive. I was locating the ball and throwing offspeed for strikes, and throwing behind in the count. I did everything you would want to in a game. It was a good tuneup, and I'm looking forward to Opening Day."

With Gee out of the game, it was a different story for the Astros, as they scored seven runs on six hits against three Mets relievers in the seventh inning to forge ahead.

Carlos Corporan's one-out two-run double preceded L.J. Hoes' two-run double, which was then followed by Matt Dominguez's RBI double. After Jonathan Villar's bunt single put men on first and third, pinch-hitter Marwin Gonzalez plated the inning's sixth run with an RBI single, and, after Gonzalez stole second on a half-successful double-steal attempt with Villar, Preston Tucker then scored Gonzalez with a single to close out the scoring in the frame.

Astros starter Scott Feldman worked 5 2/3 innings, allowing five hits and three runs, with no walks while striking out six batters. He threw 77 pitches in his final tuneup before he takes the mound for the Astros on Tuesday against the Yankees in his second career Opening Day start.

Feldman sailed through four innings before Anthony Recker blasted a two-out, two-run homer to left field in the fifth. Daniel Murphy began the sixth with a double and scored on a single by Juan Lagares to put the Mets ahead, 3-0.

Mark Appel, the No. 1 pick in last year's First-Year Player Draft, made his Grapefruit League debut by throwing a scoreless seventh inning for the Astros. Appel had an appendectomy in late January and was sent to Minor League camp before appearing in a game.

The Mets pushed three runs across in the eighth to close the gap -- the first on an Ike Davis groundout, the second on an RBI double by Andrew Brown and the last on Recker's RBI single -- before the Astros answered with two more runs to finish the scoring.

Up next: While Jon Niese and Bartolo Colon appear in Minor League games on the back fields, Minor Leaguer Cory Mazzoni will start a 12:05 p.m. ET Grapefruit League game against the Nationals on Thursday (live on MLB.TV) at Tradition Field to wrap up the club's time in Port St. Lucie. After the game, the Mets will head straight to the airport for their weekend exhibition games against the Blue Jays in Montreal.