Toronto Raptors fans may have awoken a sleeping giant with their controversial reaction to a serious injury last night.

And it's changed the tone — maybe even the course — of the NBA Finals.

It's a moment that will be discussed, dissected and no doubt debated at least until the tip-off of Game 6 on Thursday night in Oakland, Calif.

When Warriors superstar Kevin Durant crumpled to the court holding his right lower leg early in the second quarter of Game 5, some fans inside Toronto's Scotiabank Arena initially cheered. At least one courtside fan even made a waving gesture — a mocking goodbye to Durant as he sat on the court, with Durant's teammates rushing to his aid.

It was a surreal scene. The crowd continued to buzz as Raptors players — Kyle Lowry and Serge Ibaka, most noticeably — waved their arms, trying to hush the cheers out of respect for Durant. Once the fans realized the seriousness of Durant's injury (the Warriors reportedly fear it's a torn Achilles), the cheers turned into applause for the two-time NBA Finals MVP. Many Raptors fans even chanted "K-D! K-D! K-D!" as he hobbled to the locker-room.

WATCH | CBC​​​​​​'s Jamie Strashin on the Durant injury furor:

The Warriors' forward appeared to re-injure his right leg during the second quarter on Monday night. 1:07

But in the minds of Golden State players and fans the damage was already done. The Warriors and their fan base are fuming and fired up.

"Trash. So trash," Warriors centre DeMarcus Cousins later described the reaction to Durant's injury.

"Come on ... that's classless," said Warriors forward Draymond Green. "For me, I've always witnessed Canadians being the nicest people that I've ever encountered. That was classless."

WATCH | Kevin Durant suffers Achilles injury:

Steph Curry discussed his disappointment to how Raptors' fans responded when Kevin Durant left the game with a leg injury. 1:17

The knee-jerk reaction was crude, but perhaps a little more understandable when you consider the emotional state of Raptors fans. Toronto had a chance to win the NBA championship Monday night, and Durant's injury made that a stronger possibility. That's not a defence of the fans who cheered, but maybe it helps explain it.

Lowry tried to rationalize the fans' behaviour after the game.

"I don't think the fans knew the significance of the injury," he said. "They kind of [had] just seen he went down. In this league, we're all brothers. At the end of the day, we're all brothers and it's a small brotherhood and you never want to see a competitor like him go down."

Extra motivation

Throughout any gruelling series, especially a championship series, athletes and teams are always looking for something to rally around. They call it "bulletin board material" — the kind of stuff teams post in their locker-room for extra motivation.

For the Warriors, the reaction to Durant's injury — perceived or real — did just that.

This is a Golden State team that has won three of the last four titles. While the Warriors haven't become complacent, they've now been presented with a new challenge and a new way to win it all.

And don't forget, they were once the team up 3-1 in a championship series, only to watch it slip away against the Cleveland Cavaliers in 2016, the only team in history to have that happen.

Now they have some added motivation heading home for Game 6.

"The biggest advantage is being at Oracle Arena one more time, where our fans can really get behind us, and we're going to have to will ourselves for another 48 minutes to stay alive," said Warriors star shooter Steph Curry.

WATCH | Steph Curry not pleased with fan reaction to Durant injury:

CBC's Jamie Strashin recaps Toronto's 106-105 loss to Golden State, Raptors still 1 win away from championship title. 5:24

'New life'

Historic Oracle Arena in Oakland is a madhouse during normal circumstances. And Thursday will be no ordinary night. On top of that, Game 6 will be the last basketball game played in the old barn, with the Warriors moving to San Francisco next season.

The Raptors stole Games 3 and 4 there, and Toronto fans partied in the place after both wins. Warriors fans were stunned when hundreds of Raptors fans crowded into the lower bowl of the arena after the Game 4 victory last Friday, cheering and chanting and singing O Canada. Toronto fans made Oracle their own.

That sets the stage for Game 6. Emotions will be running high, fuelled by how Raps' fans reacted when Durant went down.

And you can bet Warriors fans won't want to let what took place in their house during Games 3 and 4 to happen again.

"Dub nation gonna be loud as f--k for Game 6," Durant wrote on Instagram following Game 5. "I'm hurting deep in the soul right now I can't lie, but seeing my brothers get this win was like taking a shot of tequila, I got new life."

And so does his team. The Warriors are very much alive.