BOSTON—It was up to James Shields: Did he want to face David Ortiz with first base open, or walk him to pitch to Kevin Youkilis?
Shields picked Ortiz.
What he did next was an even bigger mistake.
Shields grooved the first pitch, and Ortiz hit it over the Rays' bullpen for a three-run homer that broke a fifth-inning tie and gave the Boston Red Sox an 8-5 victory over Tampa Bay on Tuesday night.
"He did not want to throw that pitch where he did," Rays manager Joe Maddon said. "I promise you that."
Adrian Beltre had four hits for Boston, and John Lackey (9-3) won his fifth straight decision. Lackey allowed one run, eight hits and two walks, striking out three to give the Red Sox their 10th win in 13 games and help them close within one game of the first-place New York Yankees in the AL East.
Lackey and Shields (6-8) had dueling shutouts until the bottom of the fifth, when Ortiz came up with runners on second and third and two outs. Maddon came out to talk to Shields, but no sooner had he returned to the dugout than Shields threw a fastball over the plate Ortiz turned on it.
"He made a trip to the mound and I think David did a good job," Red Sox manager Terry Francona said. "David was ready for a fastball and he got it. It changed the game."
Shields has lost seven straight starts. He gave up five runs, seven hits, two walks and a hit batter, striking out six before leaving three batters into the sixth inning.
Ortiz entered the game batting .393 (11 for 28) against Shields in his career, and Youkilis was hitting .107 (3 for 28). Shields opted to face Ortiz, but the plan was not to give him anything to hit.
"I told him I wanted to face Ortiz, but I wasn't going to throw anything over the dish. I was going to try intentionally unintentionally walk him," Shields said. "I was trying to throw a fastball about a foot off the plate, just kind of show him the fastball and I ended up yanking it right down the middle. I don't even know how I did it.
"That was the turning moment of the game, I think. I've got to do a better job right there of bearing down and executing my pitch."
Beltre singled and scored to make it 5-0 after six innings, then doubled and scored on Bill Hall's homer that made it 8-1 after seven. Hall was playing second base in place of former MVP Dustin Pedroia, who broke his foot on a road trip that also took out catcher Victor Martinez and right-hander Clay Buchholz.
"You've got three masterpieces going down in three games," Ortiz said. "We've been able to have different guys come through every night."
Willy Aybar hit a two-run pinch-homer in the eighth to make it 8-3. The Rays added two more on Ben Zobrist's bloop single in the ninth, but Jonathan Papelbon struck out Aybar for his 18th save.
The Rays have won three of their last 12 games to fall behind Boston and into third place in the AL East.
Carl Crawford returned and had four hits after missing three games with left shoulder soreness. But the Red Sox took advantage of his arm: In the seventh, Youkilis scored to make it 6-1 on Jason Varitek's shallow sacrifice fly to left as Crawford's throw barely made it to the infield grass.
After Andy Sonnanstine relieved Lance Cormier, Hall homered over the Green Monster to give Boston an 8-1 lead.
Rays center fielder B.J. Upton was not in the starting lineup, but Maddon said it was not because of the outfielder's confrontation with Evan Longoria in the dugout on Sunday. The two had to be separated after Upton didn't run hard after a ball in left-center field during the Rays' 2-1 loss to the Diamondbacks.
"Just all things considered, I wanted to give him tonight off," Maddon said.
After Boston scored three more in the bottom of the seventh, Aybar cut it to 8-3. One out later, Upton came on as a pinch-hitter and tripled -- though he slowed up as he approached second base and had to turn it back on to make it to third safely. He was stranded there when Daniel Bard relieved Hideki Okajima and got Jason Bartlett to pop it up to first base.
NOTES: Red Sox SS Jed Lowrie is headed to Single-A Lowell on Saturday to begin rehabbing from mononucleosis. ... Martinez was placed on the DL with a broken left thumb. C Gustavo Molina was selected from Triple-A Pawtucket to replace him. ... Tyler Seguin, who was the No. 2 overall pick in the NHL draft, threw out a ceremonial first pitch along with Nathan Horton, whom the Bruins acquired last week in a trade. ... Aybar's homer in the eighth was the second pinch-homer of his career and the Rays' first of the season. ... The Rays designated INF Hank Blalock for assignment and activated Gabe Kapler from the DL.