Happ struck out seven over seven-plus innings of work on Wednesday, staking Toronto to a 3-0 lead before the Blue Jays lost to the New York Yankees 4-3.
The left-hander has lowered his arm slot when he throws, giving his fastball more movement and more break to his off-speed pitches.
"It obviously feels a lot more than it actually is," said Happ. "Whenever you change that up an inch or two seems like a foot. Today I felt good and for the most part maintained that slot. From a stuff standpoint it was similar but I think I had a little bit of an easier time repeating pitches and kind of using everything. It felt a little more smooth."
Happ gave up four hits, three walks and just one run but earned a no decision as New York scored three runs off the Blue Jays' (69-82) bullpen in the eighth inning for a 4-3 lead.
The victory snapped a four-game losing streak for the Yankees (80-72), who are now 2 1-2 games out of an American League wild card spot. Toronto, meanwhile, has lost six of its last eight games.
"I thought he was tremendous," said Blue Jays manager John Gibbons of Happ. "He was a different guy tonight. Hopefully that's a start. He's got to feel good about that.
"We pissed it away but he's got to feel good about that outing."
Yankees' starter Phil Hughes allowed four hits, including one home run, and two runs in 3 1-3 innings and has not won since July 2. Left-hander David Huff (3-1) allowed one run in 3 2-3 innings of relief to pick up the win. Mariano Rivera — who is retiring at the end of the season — pitched 1 1-3 innings to earn his 44th save of the season and escaped a ninth-inning jam by striking out J.P. Arencibia with runners at second and third to end the game.
The Blue Jays took their three-run lead into the eighth inning on the strength of home runs in the fourth inning by Colby Rasmus and Ryan Goins, the first of his major-league career.
Happ was replaced by left-hander Aaron Loup after Brendan Ryan led off the eighth with a double.
Curtis Granderson followed up Ryan's hit with a single and right-hander Steve Delabar replaced Loup, immediately striking out Alex Rodriguez. Robinson Cano then singled in a run and Alfonso Soriano doubled in another run.
That set the stage for former Blue Jay Vernon Wells to double in two runs and give the Yankees a 4-3 lead.
"I hung a split to Cano and he got out in front and hit it pretty hard," said Delabar. "To Soriano I thought I made a good pitch down and away and he got the head to it and I hung another pitch to Vernon."
Delabar said he was disappointed for Happ.
"He pitched a great game today," said Delabar. "We're down there trying to give him as much support as we can. Then to come in and not get the job done it's a slap in the face. Couldn't feel worse."
Rivera retired Brett Lawrie on a grounder to end the bottom of the eighth after Rajai Davis singled against David Robertson and stole second.
Adam Lind led off the ninth against Rivera with a single and Kevin Pillar pinch ran for him.
Rasmus followed with a single to move Pillar to second.
Left-handed hitter Munenori Kawasaki batted for Moises Sierra and his attempt at a sacrifice bunt resulted in a force at third. First baseman Lyle Overbay — also a former Blue Jay — got the out by playing in on Kawasaki.
"That was a great play," said Rivera who has allowed only 26 sacrifice bunts in his career, 11 by left-handed hitters.
Gibbons defended the decision to have Kawasaki bunt against Rivera and the Yankees' defence.
"He's a pretty good bunter," said Gibbons. " First and second we wanted to get the tying run to third base. It's tough to get a lot of hits in a row against Rivera. Overbay is more aggressive than most of them. If you get it down the third-base line they give it to you there. It was too much in front of home plate."
New York manager Joe Girardi had faith in his team's ability to handle a sacrifice bunt in a close game.
"I felt confident about it when they put Kawasaki in to bunt, cause (Rivera's) such a great fielder, you figure he'd make something happen," said Girardi.
Goins moved the runners to second and third with a grounder to bring up Arencibia who struck out, extending his hitless slump to 0-for-16.
"Tonight was a big game for us," Rivera said. "Being down 3-0 in the eighth inning and coming back to score four and being able to hold it, it's a huge game, huge.
"Great to see our guys put those kind of at bats together. We were able to put some runs on the board, enough to win the game."
Toronto took a 3-0 lead with one out in the fourth on two homers.
Rasmus hit a 2-1 pitch to right with one out for his fourth homer since returning from the disabled list on Sept. 13. His 22nd homer of the season scored Brett Lawrie who led off with a double.
Huff replaced Hughes and gave up a two-out homer to Goins on a 3-2 pitch.
Notes: Attendance at Rogers Centre was 24,247...The Blue Jays' 2-0 win on Tuesday was the 10th time this season the Yankees have been shut out, the most in a season since 1991 when they also were blanked 10 times. ....The Blue Jays will start RHP Todd Redmond (3-2, 4.10 ERA) against New York RHP Hiroki Kuroda (11-11, 3.13 ERA) in Thursday's series finale. ...The game will wrap up the Yankees 10-game trip that also included stops in Baltimore (3-1) and Boston (0-3). ...The Blue Jays travel to Boston for a three-game series starting Friday.