"It's a great feeling, but it's very early in the season," Rays manager Joe Maddon said. "It's not about winning. It's how we did it, with the pitching and defense and we get the hits when we needed them. We're playing the game right, and if you do that, you'll win your share of games."
Coupled with the Orioles' 6-1 loss to the Chicago White Sox, the Rays' victory gave them a share of first place. It's the latest in any season during the team's 11-year history that Tampa Bay has held a share of the division lead.
Tampa Bay has won six straight for its longest winning streak since a six-game run July 28-Aug. 3, 2005. The Rays (14-11) are three games over .500 for the first time since starting the season 3-0 in 2002. It's also the latest in the season the Rays have ever been three games above .500.
"This is huge for us," Shields said. "If you look back, this is the best April we've ever had."
Shields (3-1) struck out seven and walked one. Longoria made it 2-0 with a solo homer off Beckett in the seventh.
Beckett (2-2) struck out a career-high 13 and walked one in seven innings for the Red Sox, who have lost five straight. He allowed two runs -- one earned -- and four hits.
Red Sox designated hitter David Ortiz was out of the starting lineup for the second consecutive game. With a day game after a night contest, Boston manager Terry Francona had left fielder Manny Ramirez DH for the second time this season.
Ortiz said he probably will play on Tuesday when the Red Sox open a three-game series with Toronto.
Jason Bartlett singled with one out in the third and scored on a pair of errors during a pickoff play. He reached third when Beckett made an errant throw on a pickoff attempt and scored when right fielder J.D. Drew made a bad throw toward the plate after picking up the ball in foul territory.
"I basically lost the game for us," Beckett said. "Throw away, and the home run to Longoria."
Bartlett went 1-for-2 against Beckett, and has five hits in eight at-bats overall against him. He stayed in the game after getting hit in the helmet by a Manny Delcarmen pitch in the eighth and scored on Carl Crawford's RBI double.
"We didn't ever get anything going offensively," Francona said. "I thought Beckett was tremendous. On most nights, he throws a game like that and we're feeling pretty good about ourselves."
Beckett, who missed his last start with neck stiffness, said he felt fine.
Shields retired 10 in a row before Ramirez walked to start the fifth. Ramirez swiped second for his 35th career stolen base and first since Apr. 10, 2005. Shields worked out of trouble by retiring Kevin Youkilis on a grounder, and striking out Coco Crisp and Jason Varitek.
"I think at times we got impatient. Some of that has to do with the way he's pitching," Francona said. "He was able to command his cutter. He didn't get in any patterns. He threw the ball really well."
Tampa Bay has never swept the Red Sox in a series of more than three games. ... Rays ace Scott Kazmir (left elbow) is scheduled to make a rehab start Monday for Triple-A Durham. Maddon said Kazmir will probably start next Sunday's game at Boston. ... Boston 3B Mike Lowell (sprained left thumb) went 1-for-4 with a sacrifice fly in his third rehab game with Triple-A Pawtucket. He could rejoin the Red Sox on Tuesday. ... Tampa Bay OF Cliff Floyd (right knee) is taking part in a running program and could DH in a minor league game this week. ... Youkilis went 0-for-3 against Shields and is hitless in 13 at-bats against the right-hander. ... Ramirez is 1-for-12 overall against Shields, including 0-for-2 Sunday.