"He might be the best pitcher in baseball right now," said Orioles pitching coach Leo Mazzone, who worked with Greg Maddux, John Smoltz and Tom Glavine when he was with the Atlanta Braves. "The greatest compliment I could give him is that I have coached some of the greatest rotations, and he could fit in with any of them."
Bedard (11-4) struck out six and walked five to give Baltimore its sixth victory in seven games. Ortiz hit a two-run homer in the third that accounted for the only runs off Bedard, and a solo shot in the eighth that made it 5-3.
Bedard complained of dehydration after four innings, but he replenished his fluids and told manager Dave Trembley he would try to get three more outs. They repeated the routine after the fifth.
"When he came out of the fifth, I said, 'You're done' and he said, 'No, I want to go back out and start another inning,"' Trembley said. "He said, 'I'm feeling a little bit better,' so I let him go back out."
Jamie Walker got the last two outs for his fourth save.
"I still think one of the hardest things you can do is hit the first pitch you see out," Beckett said in an expletive-laden postgame news conference.
Asked if he took any solace in preserving the bullpen by lasting eight innings, he said, "Eight (expletive) innings instead of five? Not really."
Beckett, who also took out his anger on a dugout water cooler, allowed five runs, nine hits and two walks, striking out six to lose consecutive starts for the first time this year.
"The way they tried to attack Josh, from the first pitch of the game, it was obvious they were going to be aggressive," Boston manager Terry Francona said.
Beckett, who won his first nine starts, is 4-5 since a victory on June 8 put Boston 10½ games up in the AL East. Tuesday's loss cut the lead to just seven games over the New York Yankees, who beat the Chicago White Sox 16-3.
The Red Sox added former Texas closer Eric Gagne at Tuesday's trading deadline to help in the pennant chase, but they didn't even get to use either of the All-Star relievers they already had in the bullpen. Boston sent lefty Kason Gabbard and two minor-league outfielders to the Rangers so Gagne could take some of the load off closer Jonathan Papelbon and setup man Hideki Okajima.
Baltimore went ahead when Roberts hit a looping fly ball that landed on the top of the wall behind Pesky's Pole, about 325 feet from home plate, and bounced into the seats. It was Roberts' ninth homer of the season and his third in the last five games.
Roberts doubled and scored in the third, when the Orioles took a 4-0 lead. Ortiz cut it to 4-2 with his first homer off a lefty this season. Baltimore made it 5-2 on three consecutive hits, including Ramon Hernandez's RBI double.
Beckett retired the next eight batters.
Bedard, who leads the majors with 181 strikeouts, has allowed four earned runs in his last 35 innings.
- Ortiz had the 26th multihomer game of his career.
- RHP Curt Schilling (right shoulder tendinitis) threw 77 pitches over seven shutout innings in a Triple-A rehab outing for Pawtucket, allowing four hits and striking out four.
- The Orioles announced that Trembley will remove the interim tag from his title and finish the season.
- Red Sox RHP Mike Timlin (achy shoulder) threw 24 pitches on the side before the game and would be available Wednesday if needed.
- Boston RHP Brendan Donnelly will have season-ending elbow surgery.
- The grass in center field was dotted with sod to repair sections where the stage stood for last week's Police concert.
- The Red Sox lost for just the fifth time in 29 games against Baltimore dating to the end of the 2005 season.