TORONTO -- It has been a struggle for the Toronto Blue Jays' offense to regain that fearsome form it had last season.

Manager John Gibbons hopes that the 9-3 win over the Oakland Athletics on Saturday afternoon was the start of a return to that form.

In producing their highest run total of the season, Toronto (9-10) ended its own three-game losing streak and stopped a six-game winning string by Oakland (10-8).

The Blue Jays did it with a three-run homer by Josh Donaldson, two solo homers by Troy Tulowitzki, a career-best four hits by Ezequiel Carrera and seven innings from left-hander J.A. Happ.

The three home runs were also a season high for Toronto.

"That was a really good Blue Jays win," Happ said. "Great defense, good offense and I'd like to think the pitching was good as well. ... We came out from the get-go ready to play and that team (Oakland) is hot right now, you can tell by their at-bats."

It was the first loss on the road in eight games this season for the A's.

"It was a big day for a lot of guys, it really was," Gibbons said. We've been waiting on that kind of day. Hopefully we can build off that. It should loosen a lot of guys up."

Carrera, the fourth outfielder who was filling in for Michael Saunders in left field, also made a couple of diving catches with the most sensational coming in the ninth.

"It's one of the best games I've ever played on my life," said Carrera, who had three singles and a double.

Donaldson, who came to Toronto from Oakland last season, finished with four RBIs and three hits when he singled home Carrera in the eighth.

Mark Canha homered for Oakland.

Happ (3-0) allowed seven hits, one walk and three runs. He also hit a batter and struck out one.

"He'll get his strikeouts but he's a different pitcher than he was when he first came over here in a trade," Gibbons said. "He was a power pitcher. He got some big ground balls today to get a couple of double plays when they were needed."

Happ is 4-0 in his career against Oakland. "He's always done pretty well against us," Athletics manager Bob Melvin said. "He's had some decent numbers."

A's right-hander Chris Bassitt (0-1) allowed nine hits, two walks and six runs while striking out five in five innings.

"Not his best day but probably not as bad as it looks, numbers-wise," Melvin said.

"I didn't have my fastball all day long," Bassitt said. "It was a struggle from there on out. I had nothing today. I just didn't give us a chance."

Canha hit his third homer of the season with one out in the first inning.

The Blue Jays answered with two runs in their first.

Carrera and Donaldson opened with singles and advanced on a wild pitch. Carrera scored from third on Jose Bautista's groundout.

Tulowitzki's infield single put runners at the corners with two out. Justin Smoak walked to load the bases and Russell Martin's infield single to third scored Donaldson.

Donaldson's seventh home run of the season, a drive to center in the second, followed a single by Kevin Pillar and a ground-rule double by Carrera, which gave the Blue Jays a 5-1 lead.

Oakland scored a run in the fourth on a two-out single by Coco Crisp. It followed a double-play grounder to shortstop by Khris Davis after Jed Lowrie and Billy Butler started the inning with singles.

Tulowitzki hit his first home run of the game on the first pitch of the home fifth.

Bautista hit a sacrifice fly in the sixth against former Blue Jays right-hander Liam Hendriks to increase the lead to 7-2. Pillar started the inning with a double and Donaldson was hit by a pitch.

"I was just trying to not get him extended, trying to run it in and ran it in too far," Hendriks said. "There was definitely no intention against Donaldson. I played with him last year. Great teammate, great guy. Just a ball that slipped out and managed to get him pretty square."

When Happ hit Davis with a pitch to lead off the seventh, the teams received a warning. Davis came around to score on a single by Josh Phegley that followed a walk to Crisp and a double-play grounder by Marcus Semien.

Tulowitzki led off the bottom of the seventh with his second homer of the game and fourth of the season. The shortstop's 12th career multi-homer game gave Toronto an 8-3 lead.

Right-hander Gavin Floyd replaced Happ in the eighth.

NOTES: Blue Jays LF Michael Saunders (hamstring) was not in the lineup for the second straight game as he rests a hamstring injury. ... Toronto SS Troy Tulowitzki (hip) and C Russell Martin (neck) were in the lineup Saturday. Tulowitzki missed the game Friday after jarring his hip on a diving play Thursday in Baltimore. Martin left the game Friday after five innings because of neck spasms. ... OF Josh Reddick and C Stephen Vogt were not in the Oakland lineup against Toronto LHP J.A. Happ. ... The A's opened the season 7-0 on the road, including its 8-5 win on Friday at Toronto. They opened the 1990 season 8-0 on the road and began the 1981 season 11-0 in away games. ... The three-game series ends Sunday with LHP Eric Surkamp (0-1, 3.68 ERA) starting for Oakland against Toronto RHP Drew Hutchison (season debut), who will be recalled from Triple-A Buffalo for the start. After the game Saturday, LHP Chad Girodo was optioned to Buffalo.