All the runs and four of his hits came in the first inning. Jose Bautista hit a leadoff single before a home run to left field by Aaron Hill made it 2-0. Lyle Overbay's RBI-double later in the inning put Toronto ahead 3-0.
Toronto lefty Ricky Romero was solid, allowing five hits and one run in five innings. Romero, 13-9 with a 4.30 ERA last season, finished the spring with a 1.89 ERA in five starts.
Houston picked up the 29-year-old Myers from Philadelphia this offseason after he was the Phillies opening day starter the last three seasons.
Myers, who spent eight seasons with the Phillies, admitted he was a bit nervous playing for the first time as an Astro in Minute Maid Park.
"I was a little jittery the first inning, playing in Florida and not with the lights on and everything like that, it kind of got me a little pumped up," he said. "Was leaving the ball up in the first inning a little bit. But I made the adjustments."
Astros manager Brad Mills thought Myers was a bit too worked up early.
"It's a little bit different coming out here than it is during spring training, and his command just wasn't there," Mills said. "He just had too much of the plate, but he made some adjustments and came back and started pitching."
Myers, who was starting his team-high sixth spring game, retired nine of the next 10 batters after Overbay's double before hitting Edwin Encarnacion with a pitch with one out in the fourth. He said he felt great after a week's rest following the injury that caused him to leave after 5 1/3 innings March 25.
He said he wanted to work on his fast ball, but that he soon changed things up after they were hitting his fast balls.
"That's what I wanted to work on but after that I was just kind of like: 'I'm not going to let them get the best of me. I'm not going to try to give up six runs just because I'm going to work on some pitches," he said. "So I think my competitiveness took over and I just started pitching."
The Astros wanted to keep his pitch count around 80 and he left with 82, but felt like he could have pitched to 100.
"Smart move," he said of being pulled. "I feel strong now, so why not try to stay strong, no sense in putting any more stress on anything because we've got 162 of these to go and hopefully I've got 35 (starts) in me."
"Ricky did fine, he did great," Blue Jays manager Cito Gaston said. "He didn't have his good location but he battled out there and kept us in the ball game. He wasn't the sharpest he can be but it just shows how he's moving forward."
Houston added a run in the eighth inning to make it 3-2 when Jason Michaels scored when Humberto Quintero reached on a fielders choice. The Astros tied it up in the ninth when Chris Shelton's double that bounced off the low wall in right field sent Cory Sullivan home.
Adam Lind doubled in the 10th inning but the Blue Jays couldn't score. Rommie Lewis pitched a 1-2-3 inning for Toronto to end the game.
The game, which is the first of two to end Houston's spring schedule, is Toronto's first visit to Houston since June 2005. ... The Blue Jays will stay in Texas for their season opener against the Rangers on Monday.