TORONTO -- Clay Buchholz's reward for winning his season debut? A ticket back to Triple-A Pawtucket.
"[Buchholz] was awesome," teammate Dustin Pedroia said. "He threw every pitch in any count. You could tell he was frustrating those guys."
David Ortiz added a two-run double as Boston opened the second half by winning its fourth straight.
Toronto has lost 13 of 16 to drop a season-high three games below .500.
Called up from Pawtucket, where he was 7-2 with a 2.36 ERA, Buchholz (1-0) made his first major league start since Aug. 20. The win was his first since May 2, 2008.
"It feels like about three years," Buchholz said.
Red Sox manager Terry Francona was impressed with Buchholz's composure.
"Considering the circumstances and everything, I thought he had poise, I thought he had good stuff," Francona said. "He attacked with his fastball, he threw his changeup, he threw his breaking ball. He commanded the game. It's really gratifying for us. We've heard all the reports and we've seen him work but then to see him do it tonight was a lot of fun for us."
Buchholz threw a no-hitter against Baltimore in his second career start in 2007. He struggled last season and was sent to the minors on Aug. 21 after going 0-7 with a 9.21 ERA in his previous 10 games.
"I was fighting an uphill battle last year, coming into a game, because it felt like I was already down before I even stepped out on the field," Buchholz said. "This year's been a different story. I definitely feel a lot better as far as going out there and being confident."
Against Toronto, the right-hander allowed one run and four hits. He left after a two-out single by Lyle Overbay and a walk to Alex Rios put runners at first and second. Daniel Bard came on and struck out Jose Bautista to end the inning.
Buchholz knew in advance he'd be going back to Triple-A no matter what he did against Toronto. Boston's rotation is already set and the club used Buchholz to give its starters an extra day of rest after the All-Star break.
"I'm just thankful for the opportunity to be here and play with these guys again," he said. "The starting rotation they have here right now is pretty unbelievable."
Blue Jays rookie Ricky Romero (7-4) lost for the first time in seven starts, allowing four runs and five hits in 4 1/3 innings. The lefty matched a season high with five walks and struck out eight.
"He didn't have his command tonight, he walked five guys," Blue Jays manager Cito Gaston said. "He had eight strikeouts but it was the walks that killed him tonight."
Youkilis connected for his 17th homer in the first and Ortiz doubled off the top of the left-field wall in the fifth to give the Red Sox a 4-1 lead.
"Youk got a fastball and gave us a lead, which is a good way to play because Romero has got one of the best left-handed changeups in the game," Francona said.
Rios hit a sacrifice fly in the fourth for Toronto.
- The Red Sox are expected to activate SS Jed Lowrie (wrist) before their game against Toronto on Saturday.
- OF Jacoby Ellsbury (illness) was scratched from Boston's lineup and replaced by Rocco Baldelli.
- The Blue Jays were without OF Vernon Wells (stomach virus).
- Overbay had three of Toronto's five hits.
- Blue Jays LHP Brian Tallet, who has won just once in six starts, will pitch out of the bullpen for now as the Blue Jays use off days to go with a four-man rotation over the next few weeks.
- Toronto signed its fourth-round pick in June's draft, SS Ryan Goins from Dallas Baptist University.