TORONTO -- Ricky Romero spent the past two winters tinkering with his changeup.
All that extra work is starting to pay off.
Romero pitched four-hit ball over eight innings, Rod Barajas, Adam Lind and Scott Rolen each homered and the Toronto Blue Jays ended the Tampa Bay Rays' seven-game winning streak with a 5-0 victory Wednesday.
"[Romero] throws a decent fastball but he has an above-average changeup," Tampa Bay slugger Pat Burrell said. "He was mixing it up and locating it fairly well. We just weren't able to make the adjustment."
Barajas said Romero's off-speed pitch has few equals.
"I've caught some good changeups and he's right up there with the best I've caught," Barajas said.
A first-round draft pick in 2005, Romero didn't reach Triple-A until last season after scuffling in the low minors. Finally harnessing his changeup helped him land him a rotation spot with Toronto this spring.
"That was one of my pitches the past two offseasons," Romero said. "Just working on that pitch, trying to throw the hell out of it when I played catch. It's becoming better and it's just getting better every time."
Romero (6-3), who took a no-hitter into the seventh in his last start, matched the longest outing of his career in winning his third straight start. He walked four, struck out seven and lowered his ERA to 2.85. The rookie left-hander allowed just two hits through the first six innings.
"I'll ride this little thing I've got going for as long as I can," Romero said.
Romero is 5-1 in his past six starts and has not allowed a run in his past 20 innings.
"He's good," Rays manager Joe Maddon said. "He's going to be very good for a long time if he stays healthy."
Jason Frasor pitched the ninth to complete the four-hitter, the Blue Jays' sixth shutout.
Toronto snapped a four-game losing streak thanks to a trio of solo home runs off James Shields (6-6).
Barajas connected with one out in the seventh. Lind and Rolen hit consecutive shots in the eighth, the third time this season the Blue Jays have gone back-to-back.
Toronto's defense helped Romero get out of a jam in the seventh, when the Rays loaded the bases with two singles and a walk. Romero escaped by getting Burrell to ground into a double play.
"That was the key to the game, the last two innings," Romero said. "Bases loaded, one out, you've got a good hitter up in Burrell. I just made a good pitch that got in on him and we were able to get a double play."
A walk and an error by shortstop Marco Scutaro gave the Rays runners at first and second with none out in the eighth. Scutaro redeemed himself by catching a line drive from pinch-hitter Willy Aybar and then flipping to second to get Jason Bartlett for the double play.
"We had chances, we just didn't get it done," Burrell said. "We got close a couple of times."
James Shields allowed five runs -- four earned -- and seven hits in 7 1/3 innings. He walked one and struck out eight.
"I felt great, I thought I batted today," said a frustrated Shields, who dropped to 1-4 on the road.
Shields retired the first eight Toronto batters before Jose Bautista hit an infield single in the third. Scutaro followed with an RBI double down the left-field line, his first hit in 18 at-bats.
Rolen extended his hitting streak to a career-high 19 games with a single in the sixth and Overbay snapped an 0-for-16 skid with a single in the eighth.
Toronto outfielder Vernon Wells, stuck in a 2-for-19 slump, was held out of the starting lineup and was booed when he came on as a defensive replacement in the ninth. With Wells out, Lind batted third for just the second time this season while Overbay hit fifth. ... The Blue Jays celebrated Canada Day with red caps and jerseys. Canadian-born Hall of Fame pitcher Ferguson Jenkins threw out the first pitch and a group of fans in right field hung maple leaf signs instead of Ks to mark strikeouts... This was the first of five straight day games for Toronto, who begin a four-game series at Yankee Stadium on Friday.