"I couldn't really get enough on it and [I was] off-balance and facing the wrong direction," Casey said of his shot. "I tried to keep it looping and hoped that somebody was in the right spot, and once again Jack was in the right spot."
McInerney, who had a goal nullified in the 89th minute when it was ruled teammate Amobi Okugu obstructed keeper Joe Bendik, wasn't to be denied this time. The fourth-year Union forward now has four goals, including two game-winners.
The chippy game included nine yellow cards _ six on Toronto.
Union center back Jeff Parke, who had another stellar game, called it the most physical game of the year.
"It was [chippy] _ but there were so many little fouls and the refs didn't let us play," he said.
Toronto (1-2-3) scored the game's first goal in the 71st minute. Defender Ashtone Morgan sent Robert Earnshaw on goal with a long ball and Toronto's leading scorer got his fifth goal while beating keeper Zac MacMath on a breakaway.
Morgan would later leave the game after receiving his second yellow card in the 88th minute.
This marked the debut of Union designated player Kleberson, the Brazilian who replaced defender Ray Gaddis in the 79th minute but moved up to midfield and gave the attack a major boost.
"It was very cool," Kleberson said through an interpreter. "It was also a lot different, a lot more physical than I expected."
Former Union captain Danny Califf, playing for Toronto, got a huge pregame ovation. Califf, who started the first four games but missed last week's 2-2 tie against FC Dallas because of illness, didn't play.
"We've got some good center backs as you saw today and it's hard to get in games," Toronto coach Ryan Nelsen said when asked about Califf.
Contact Marc Narducci at firstname.lastname@example.org. Follow @sjnard on Twitter.