TORONTO -- The Blue Jays' first series of the year against the Red Sox is going to be used as a measuring stick to see how they match up with arguably the top team in the American League East. Curtis Granderson and J.A. Happ made sure they passed the first

TORONTO -- The Blue Jays' first series of the year against the Red Sox is going to be used as a measuring stick to see how they match up with arguably the top team in the American League East. Curtis Granderson and J.A. Happ made sure they passed the first test with flying colors.

Granderson threw out the potential go-ahead run in top of the ninth inning and then hit a walk-off solo homer in the bottom of the 10th as the Blue Jays overcame Roberto Osuna 's first blown save of the year in a 4-3 victory over the Red Sox.

Happ came away with a no-decision, but he played a big role in the win by limiting Boston's offense to one run over seven strong innings.

"I'm trying to just do anything I can to help the team win and put ourselves in an opportunity to win," said Granderson, who has eight RBIs over his last five games. "Starting in right, starting in center, starting in left, trying to get on base, I'm just trying to do the little things, because this team has such a great ability to come up in big situations."

It was the fourth walk-off home run of Granderson's career, and it came on a 2-0 fastball from Red Sox closer Craig Kimbrel . Toronto picked up its second walk-off victory of the year and improved to 2-0 in extra-innings games this season. Granderson went 3-for-5 with his third home run of the season.

Tuesday's game marked the first of 18 games between the two clubs. The Red Sox, along with the Yankees, have long been considered the favorites in the division, but the Blue Jays have been turning a few heads with their early season play. The victory in the series opener ensured that Toronto will finish March/April with at least a .500 record, something that hasn't happened since 2012.

One win might not seem like much, but it's a symbolic victory for a Blue Jays team that entered this game having lost eight consecutive games to Boston at Rogers Centre. Last season, Toronto was outscored 107-75 by the Red Sox, and its -32 run differential vs. the Sox was the organization's lowest since posting a -51 against the Rays in 2012. Something has to change if the Blue Jays are going to be taken seriously in the division, and Tuesday was a good start.

Happ never had multiple baserunners at any point during his fifth start of the year. He frequently used his four-seam fastball up in the zone to generate swings-and-misses from the Red Sox as he picked up double-digit strikeouts for the first time since Aug. 2, 2017, vs. the White Sox. The 35-year-old averaged 92.7 mph with the four seamer while mixing in his slider and curveball combo 20 times in his strongest outing of the year.

"We remember that they've played well here, so it's nice to set the tone and get that first one here," Happ said. "I think it's something that's going to be a battle all season long. I think these are two really good ballclubs and that we'll see a lot of games pretty tight like this one."

MOMENTS THAT MATTERED

Can't close it out: Osuna got himself into all sorts of trouble in the top of the ninth inning. Hanley Ramirez and Rafael Devers singled to put runners on first and second with one out while Eduardo Nunez followed with an RBI single. Later in the frame, Boston loaded the bases as Brock Holt delivered the game-tying run with an RBI single to left field. It could have been a lot worse, but Granderson saved the day by throwing out Nunez at the plate on Holt's RBI single, which eventually forced extra innings. Osuna picked up his first blown save of the year in seven attempts and also surrendered his first earned runs of the season.

"That's the way baseball is sometimes," Blue Jays manager John Gibbons said. "I think that was Osuna's and Kimbrel's first runs they've given up all year. That's why you call it the big leagues … The guys battled. That was a big game for us. If you don't win that one, it's a kick in the teeth."

The fortunate bounce: The Blue Jays opened the scoring in the bottom of the second when they had runners on the corners and Boston third baseman Devers was unable to field a grounder and make a throw home in time to get a sliding Steve Pearce. Later in the frame, Devers was put under the spotlight once again with a pair of runners on base. This time, Granderson hit a hard grounder that deflected off Devers' glove to allow two more runs to score.

SOUND SMART

Over the previous five years, Toronto had the worst March/April record in the Major Leagues, going 52-75 (.409). A year ago, the Blue Jays did not pick up their 14th victory until Game No. 35 on May 11. This season, they reached 14 wins in Game No. 24 on April 24.

HE SAID IT

"I think the city is hurting right now and we had some first responders here today. I hope they enjoyed the game, if they stayed until the end, which I think they did. I think it was a meaningful win for us on several levels." -- Happ, when asked about the importance of winning the series opener as he referenced Monday's tragic events in Toronto that saw multiple casualties following an attack involving a white van

YOU GOTTA SEE THIS

The Blue Jays were in a perfect position add another insurance run when Teoscar Hernandez stepped to the plate in the bottom of the fifth. With a runner on second, Hernandez hit a sharp liner to right field that appeared destined for extra bases, but Mookie Betts had other ideas. According to Statcast™, Betts covered 53 feet in 3.5 seconds to make a four-star grab that came with a catch probability of 31 percent. Yangervis Solarte followed by lining out to second base and the Blue Jays came up empty in the fifth.

UP NEXT

The Blue Jays will continue their three-game series against the Red Sox when Aaron Sanchez (1-2, 3.86 ERA) takes the mound on Wednesday night with first pitch scheduled for 7:07 p.m. ET. Sanchez has experienced a dip in velocity so far this season. In 2017, he averaged 95.0 mph on his two-seam fastball, but in a recent outing against the Yankees, that number dropped to 92.8. The velocity has not impacted his performance with three quality starts in four outings. Boston will counter with left-hander Eduardo Rodriguez (2-0, 3.45 ERA).