The Raptors stunned the Warriors with a 131-128 victory in overtime to pick up their 16th win in their 44th meeting.
Warriors were without Steph Curry and despite being down for the entirety of the game, somehow managed to take the game to overtime.
Kevin Durant top scored for the Warriors with 51 points and produced 11 rebounds.
Leonard was on fire for the Raptors and he weighted in with 37 points to keep his side atop the Eastern Conference, taking their record for the season to 19-4.
However, he refused to get carried away by the victory.
When asked for his thoughts on the Raptors’ win over the Warriors, Leonard said: “It’s just a building point for us.
“They’re still the champions.
“It’s still a regular season game.
“It’s not even December yet.
“We just have to keep pushing and try and get better.”
Meanwhile, Curry is expected to return for the Warriors against the Detroit Pistons on Saturday night.
Having missed the last 10 matches with a groin injury, Curry will be fit soon.
NBA on TNT reporter Kristen Ledlow said before the Warriors’ loss: “He [Curry] was going through his progressions behind me, but I was told by a member of the Warriors staff prior to the game that they were concerned by the length of the trip to Toronto and Steph’s susceptibility to injury.
“If it were a play-off game he would be playing.
“One of the things though that coach Kerr told is that it is ‘killing Steph’… he spent some of his childhood in Toronto.
“He wanted to play in this game, but the team essentially thought there would be no need to rush him.
“He’s expected to make his return on Saturday.”