TORONTO -- Right-hander Nathan Karns needed just one swing of the bat for his first major league win.

Tampa Bay catcher Ryan Hanigan provided it with a solo homer to lead off the third inning. Karns did the rest, riding out a rocky opening to hold the Blue Jays to two hits over seven innings as the Rays blanked Toronto 1-0 Friday night.

The end result was the first major league win for Karns (1-0), summoned earlier in the day from triple-A Durham. The 26-year-old Karns, who made his three previous big league appearances last year with Washington, struck out eight while walking two.

"I thought he was pretty damn good," Toronto manager John Gibbons said. "The chance to get him was in the first when he had trouble with the (strike) zone. He didn't throw a lot of strikes ... Then after that things clicked for him. I thought Hanigan did a great job with him behind the plate."

Karns walked two and hit a batsman in the first. But he was rescued by a double play in an inning that saw him throw 25 pitches with only 10 strikes.

The Jays wasted a fine performance by left-hander J.A. Happ (9-10), who struck out seven and walked one while giving up just two hits in seven innings.

"He (Karns) was great tonight. Happ was great," said Gibbons. "The difference was that solo home run. If you love good pitching, you saw it."

Said Rays manager Joe Maddon: "He (Karns) got to the point where he had to throw a strike, he could ... He did a nice job. That really exceeded expectations."

Jake McGee pitched the eighth for the Rays (71-77) before Australian Grant Balfour came on in the ninth for his 12th save.

Toronto (76-70) came into the game having won four straight and nine of its last 11. Jays pitchers had posted an earned-run average of 2.36 during those 11 games, nosing the team back up the wild-card standings.

Jays bats were hot in a three-game sweep of the Chicago Cubs at the start of the week that saw the National League visitors outscored 28-3. But they were quiet against Tampa as both teams managed just two hits on the night.

The Rays had lost two straight and three of their last six. Tampa blew leads of 4-0, 4-0 and 3-0 in those losses.

The Jays let Karns off the hook in the first inning before 19,909 under the roof at the Rogers Centre, failing to take advantage of men on first and second with no outs. Karns settled down and did not give up a hit until the fourth inning -- a Danny Valencia double. Adam Lind, with a single in the sixth, was the only other Jay to get a hit off the right-hander.

"The nerves were a little overwhelming at first but then they wore off and everything settled in," said Karns.

Happ came into the game with a 1-3 record in his last eight starts. But he threw strikes for 10 of his first 11 pitches and struck out the side while walking one in the first.

Happ retired six of the first seven batters he faced before yielding the solo homer to Hanigan to left field to lead off the third. It was the fifth of the season for the Rays catcher and the first since coming off the disabled list on Aug. 26.

"You guys are probably going to say that's a mistake. I don't really consider (that)," said Happ. "If being aggressive, throwing at the glove and trying to get ahead is a mistake, then it was a mistake. I think he just kind of guessed right and ambushed it and got enough of it."

Happ retired 14 of the next 15 next batters he faced until a Jose Reyes error put a man on base.

"You expect to win most of those games," said Happ, who said he took no positives from the evening.

It marked the seventh time this season he has thrown six-plus innings while limiting the opposition to one earned run or less. Happ has gone six-plus innings in seven of his last eight outings, during which time he has received just 16 total runs in support. The team has lost seven of those games.

Aaron Sanchez came on for the Jays in the final two innings.