MONTREAL — It was the scenario everyone wanted — the Olympic Stadium crowd, the Toronto Blue Jays and their blue-chip prospect Vladimir Guererro Jr.

And the son of Montreal Expos legend Vladimir Guerrero came through in style.

The 19-year-old got the last at-bat of the game with two out in the bottom of the ninth and hammered a hanging slider from Jack Flaherty over the left-centre field wall to give the Blue Jays a 1-0 victory over the St. Louis Cardinals on Tuesday night.

The throng of 25,816 went bananas and called the youngster out for a curtain call.

"Usually at the end of this game everyone's ready to get out of here," manager John Gibbons said as the Blue Jays ended their pre-season schedule. "We came in and the guys were celebrating with him.

"You don't see many celebrations in spring training games. That was pretty neat."

The Montreal fans had given Guerrero Jr. a standing ovation just for taking the field at third base during a 5-3 loss to St. Louis on Monday night.

They remember the many home runs, stolen bases and amazing outfield catches his father made in the same stadium from the late 1990s until he left in 2002, two years before the Expos moved to Washington D.C. Vladimir Sr. is headed to the baseball Hall of Fame this summer.

Vlad Jr. is different in many ways. He's an infielder. He's patient at the plate where his father was the ultimate free swinger. But perhaps a cool head and a flair for the dramatic are hereditary.

"I had a great pitch to hit," Guerrero Jr., said through an interpreter. "I didn't feel so much pressure.

"I was just trying to do my best and have fun. He hung it and I took advantage of it."

Guerrero Jr., was born in Montreal and was a regular at the Olympic Stadium as a toddler, although he doesn't remember much except for the ice cream machine in the Expos clubhouse.

Now he has a better Big O memory.

"These two days have been amazing for me," said Guerrero, who is slated to continue his development in double-A ball this season. "It's like a dream come true. Of course having that chance to help the team win is something I'm always going to remember."

It had been a forgettable game up to then. Five Toronto pitchers struck out 10 Cardinals and four St. Louis pitchers fanned 11 Blue Jays. Guerrero's homer was only the Blue Jays' third hit of the game.

Gibbons said Guerrero was placed in the batting order when he entered the game in the sixth in a spot where he might have at least two at-bats. He rewarded them with a walk-off home run.

"That was unbelievable," said Blue Jays veteran and Montreal product Russell Martin. "Everyone was jumping for joy.

"Ecstatic. The energy level went through the roof. I'm surprised the roof is still on the stadium, to be honest. He knocked the seams off that ball. It's just a special moment for the kid, for us. What a great way to finish spring training."

Guerrero had come close in his first at-bat in the sixth but was thrown out at first after a hard ground ball up the middle.

Toronto ended the pre-season 14-18 while St. Louis went 17-13.

Martin started at third base as Luke Maile took over behind the plate.

Blue Jays starter Joe Biagini went five innings, allowing five hits and striking out six.

The Cardinals pre-game batting practice ended early as a 20-minute power outage hit Olympic Stadium and the surrounding neighbourhood.

Several Montreal Canadiens players took batting practice before the Blue Jays, including defenceman Jeff Petry whose father Dan Petry pitched, mainly for Detroit, in the 1980s.