Gay scored 19 of his 21 points during a dominant third quarter and the Raptors ended a five-game skid with a 99-82 victory over the Detroit Pistons on Friday night.
Toronto led 46-45 at the break and took control by outscoring the Pistons 23-5 in the first eight minutes of the third period.
DeMar DeRozan also had 21 to help Toronto win a second straight meeting with the Pistons.
"Whatever he drank at halftime, he needs to keep drinking it," coach Dwane Casey said of Gay, who was 7 for 11 from the floor in the third.
"Something clicked at halftime to get him going."
Gay had just two free throws in the first half, but heated up quickly once the teams returned to the floor. He scored eight of the Raptors' first 10 second-half points and added two 3-pointers later in the period to help turn the game into a rout.
"We've got a lot of young players and we're playing for next year," Gay said. "These young guys need to know what it feels like to win."
Amir Johnson added 20 points, including 10 during the second period that helped the Raptors take the lead for good.
Jonas Valanciunas had 14 points and 13 rebounds and Kyle Lowry added 11 assists.
"Rudy picked it up in the third and DeMar got it going, too," Lowry said. "When they get going, it's hard to stop them."
Jonas Jerebko scored 20 points to lead the Pistons, who also got 17 from rookie Andre Drummond in their eighth straight home loss. Detroit made just six field goals in the third and often couldn't seem to stop Gay once he got hot.
"It just doesn't add up when you're competitive for a half," an exasperated Pistons coach Lawrence Frank said. "It just snowballed on us.
"This is embarrassing."
The Pistons turned the ball over four times in the third and Toronto turned the miscues into nine points. Detroit ended the game with 13 giveaways.
Drummond, who missed 22 games with a stress fracture in his lower back, made his first career start and played for the first time since leaving a Feb. 6 loss to Brooklyn.
Kyle Singler added 13 points and Greg Monroe added 11 points and 13 rebounds as Detroit fell for the 12th time in its last 13 games.
It was the first time Toronto played against Pistons point guard Jose Calderon since the Jan. 30 trade that sent longtime Raptor Calderon to Detroit, Tayshaun Prince to Memphis and Gay to Toronto.
NOTES: Pistons guard Brandon Knight left the game less than a minute in after a collision with Toronto's DeRozan left him with a bloody nose. He returned a few minutes later wearing a protective mask and limped off the floor after being fouled midway through the fourth quarter. . It was '90s Night at the Palace of Auburn Hills. Actor Luke Perry of "Beverly Hills 90210" fame presented the game ball. . Longtime Pistons trainer Mike Abdenour is resting at home after having a stent procedure placed for a heart condition that was discovered March 24. He's been with the team for 34 seasons.Suggest a correction