10/14/2012 04:13 EDT | Updated 12/14/2012 05:12 EST

Richardson and Emry lead Alouettes to 24-12 win over Argonauts in East battle

TORONTO - Jamel Richardson couldn't have picked a better time to register his first 100-yard receiving game of the season.

Richardson and Shea Emry scored second-half touchdowns Sunday to give the Montreal Alouettes a 24-12 victory over the Toronto Argonauts — and a home playoff date.

Richardson scored on a 75-yard touchdown reception at 12:25 in the third quarter for the East Division leaders, injecting some life into what had been a dreary game in front of 25,348 fans at Rogers Centre.

Richardson beat Toronto's Pat Watkins for the ball before sprinting down the sideline to give the Alouettes a 17-12 lead. The long-distance catch also gave Richardson his first 100-yard game this season after he collected a CFL-record 12 last season when he led the league in receiving.

"Better late than never," Richardson said, smiling. "At the right time, right place."

Emry picked off a Jarious Jackson pass intended for Jason Barnes at 6:17 in the fourth quarter and ran 46 yards to give the Als a 24-12 lead. It was Emry's first interception for a touchdown and Montreal's first this season.

"I think he made a great play," Jackson said. "Did my read, never saw him sneaking his way up the middle."

The game was a huge one with first place in the East on the line between two teams battling for post-season positioning. The victory put the Alouettes (9-6) in the driver's seat, leading Toronto by four points with three games left and owning the tie-breaker.

"I was proud of our team today and certainly our defence stepped up and played a very good football game," said Montreal coach Marc Trestman. "It was a great team effort, probably as good as we've had this year.

"Games can unfold a lot of different ways, you don't have to score 45 points to win a game sometimes. Sometimes you've just got to keep sawing wood. And our guys did, they didn't lose their focus. "

Toronto dropped to 7-8 with their fourth loss in five games.

"Certainly was an opportunity lost, like last week (a loss to Saskatchewan)," said Argos coach Scott Milanovich. "My mantra all season was to win the East. Keep their goals high. That's probably lost now."

Finishing first in the division means a first-round playoff bye, then an East final played at home. The second-place finisher will host the East semifinal, with the winner of that game advancing to the conference final.

The Argos defence doubled key players, including Richardson, for most of the afternoon, and Trestman said it was a "chess match" trying to unlock receivers to give them single coverage.

"(Anthony Calvillo) waited it out and J-Rich made a big play at a very important part of the game," Trestman said. "It was good to see him get that ball, have a chance to make a contested catch and do something with it."

Richardson said he didn't allow the double coverages to get him frustrated.

"I came in here with my peaceful mind," the slotback said. "I was at ease, I was going to let the game come to me. . . we knew it was going to be a matter of time when I was going to get single coverage and (the Argos) were going to blow one."

Milanovich believed the Argos had Richardson contained.

"We had good coverage," the coach said. "They just chucked it up there and he went and got it,"

Calvillo, who's now 12-2 in 13 straight starts against Toronto, was 16-of-31 for 255 yards, one touchdown and one interception.

"Man, I'm just sitting here absorbing this," the veteran quarterback said. "I'm tired, but these young guys in this locker-room played with the backbone that we needed, it's exciting. But we're going to continue to need that as we move forward, but we're going to continue to enjoy this."

The Als also played a good chunk of the game without receiver Brandon London and then lost Eric Deslauriers with five minutes to go. London left the game with a knee injury with five minutes to go in the first half while Deslauriers hurt his ribs.

"You've got to have heart," Trestman said on his team's composure in the midst of injuries. "You don't see that in the stats. That's what our team showed today was a collective heartbeat and they played with an edge, they played hard. It wasn't perfect, it never is."

Andre Durie scored Toronto's lone touchdown on a 24-yard catch 7:39 into the second quarter to stake Toronto to a 9-2 advantage. Durie evaded a tackle before taking a sharp right turn and headed for the open end zone for his second touchdown of the season.

Jackson, making his third consecutive start in place of injured No. 1 quarterback Ricky Ray, was 20-of-40 for 239 yards, one touchdown and an interception for a touchdown.

Argos kicker Noel Prefontaine played his first game after missing 13 with hip surgery last July that he had feared may end his career. The veteran, who had said a day earlier he would only do punting duties as he eased himself back into game action, got Toronto on the scoreboard, booting a 57-yard single 2:21 minutes into the game.

He added a 59-yard single at 11:11 in the first quarter, but bobbled the snap and then was forced to avoid the rush. The Argos led 2-0 to start the second.

Sean Whyte scored Montreal's only points of the first half, booting a 48-yard single at 2:06 into the second quarter, then field goals of 35 and 27 yards. His second came on the last play of the first half and capped an 81-yard drive highlighted by a 47-yard catch by Deslauriers. The Als had to settle for three points, and the Argonauts led 9-7 at halftime.

Whyte connected again on a 37-yard field goal at 8:30 to put the Als up 10-9.

Toronto kicker Swayze Waters had four points on a 37-yard field goal and a convert.

The matchup was designated a CFL Pink game and players wore bright pink on their shoes and wrists, while the coaching staffs wore pink jackets in support of awareness and fundraising for women's cancers. Fans in pink wigs, glasses and baseball hats dotted the crowd.

NOTES: Defensive backs Wopamo Osaisai, Ed Gainey, guard Kristian Matte, and defensive end Chima Ihekwoaba didn't dress for the Alouettes, while cornerback Ahmad Carroll, wide receiver Maurice Mann, linebacker Kyle Jones, and offensive lineman Joel Reinders didn't dress for Toronto.