Updated

For the struggling Blue Jays, what started as a soaker soon turned into a real stinker.

Mark Reynolds hit a three-run homer, Zach Britton pitched seven innings to win his fourth straight start and the Baltimore Orioles moved into a first-place tie in the AL East with a 12-0 victory over Toronto on Tuesday night.

Mechanical troubles with the retractable roof at Rogers Centre left the field slippery and damp during the middle innings as rain fell inside the stadium. The team apologized to fans after the roof was unable to close at the normal speed, leaving many people opening umbrellas to protect themselves from the elements.

Blue Jays pitcher Carlos Villanueva was among those caught off guard by the surprise shower, leading to what he called "a very adventurous couple of innings."

"We were definitely not prepared for that," Villanueva said. "We have nothing behind the mound. Usually on other mounds you have something for your cleats. I could feel my cleats getting heavy."

Villanueva (7-5) lost for the fifth time in seven starts, allowing a season-high six runs and seven hits in 6 2-3 innings.

"I can say a million things about what happened out there with the roof, but the fact of the matter is it happened," Villanueva said.

Groundskeepers had to use drying agents on the mound and dirt cutouts around the bases before the bottom of the sixth inning as rain continued to fall on the infield.

"I don't even know why they opened it in the first place," Reynolds said. "It was raining outside all day."

Indeed, Toronto broke a 31-year record for rainfall Tuesday, as the remnants of Hurricane Isaac dumped more than 1½ inches of rain on the city by 2 p.m.

The roof slowly inched to a close, finally snapping shut in the bottom of the seventh.

Struggling Toronto has dropped four straight and was held scoreless for the second straight game, the first time that's happened since May 2008. The Blue Jays fell to 15-25 when facing a left-hander.

"It's clear we've had some issues against left-handed starters," manager John Farrell said.

Baltimore's third consecutive victory coupled with the Yankees' loss at Tampa Bay gave the Orioles a share of first place in September for the first time since 1997, the last time they won the division and advanced to the playoffs.

"We're just having a good time and we're not putting pressure on ourselves," Reynolds said. "Everybody knows the situation we're in but we're just taking it day by day and having fun."

The Orioles also lead the AL wild card chase, with the Rays 1 1/2 games back in both the division and wild card standings.

"It's a big deal, obviously, but there's a lot of games left," Reynolds said. "Us, the Yankees and the Rays are all right there. Oakland is having a good run right now. We can't take anything for granted."

Reynolds went 3 for 4 with four RBIs as the Orioles pounded out a season-high 18 hits.

Recalled from Triple-A Norfolk to face the Blue Jays, Britton (5-1) allowed four hits and improved to 4-0 with a 0.94 ERA in four starts since his last loss on Aug. 1 against New York. The left-hander struck out eight and walked two, one intentional.

"He's really in a good place right now," Orioles manager Buck Showalter said. "He was pretty relentless tonight, he kept pounding the zone."

Kevin Gregg worked the eighth and Zach Phillips finished for the Orioles, who have won three straight and 21 of 29.

Reynolds hit his 17th homer off Villanueva in the fifth. It also was his fifth homer in five games.

Nate McLouth added a sacrifice fly in the sixth, and the Orioles pulled away with a three-run seventh. Robert Andino chased Villanueva with a sacrifice fly, Aaron Loup's balk scored Manny Machado and J.J. Hardy singled in Nick Markakis.

Baltimore added five more runs against Loup and Chad Beck in a 10-batter seventh. Chris Davis hit an RBI double, Reynolds and Machado each singled in a run, Markakis tacked on an RBI double and McLouth capped the outburst with an RBI single. The Orioles left the bases loaded when Adam Jones grounded into a double play.

NOTES: The Blue Jays had a 26-minute delay in July 2003, when a sudden storm drenched the field before the roof could close during a game against the Chicago White Sox. ... The shutout was Baltimore's ninth of the season, seven of which have come on the road. ... Orioles RHP Jason Hammel is expected to come off the 15-day disabled list to start Thursday in the opener of a crucial four-game series against the Yankees in Baltimore. ... Baltimore LHP Chris Tillman underwent an MRI. Tillman, who left after three innings of Sunday's victory over the Yankees, has no structural damage but is suffering nerve inflammation. It's not known when he'll pitch next. ... The Blue Jays recalled Beck and OF Anthony Gose from Triple-A Las Vegas. ... Orioles minor league LHP Kevin Grendell has been suspended 50 games after testing positive for a banned substance. ... Attendance was 13,556, Toronto's smallest crowd of the season.