Raptors head coach Nurse has taken a large portion of the blame for the 106-105 defeat because he called for a late timeout while his team were on top.
They also had to opportunity to cap off a remarkable season against weakened opposition as Durant suffered a potential torn Achilles injury.
Toronto headed into the crunch showdown with a 3-1 lead in the NBA Finals.
They knew victory would have taken the Championship to Canada with two games to spare.
However, the Warriors are desperate to defend their title and gambled by naming Durant in the starting line-up.
The small forward was rushed back from a previous issue and only lasted 12 minutes at the Scotiabank Arena before having to withdraw with an Achilles injury.
Durant is set to have an MRI scan to reveal the true extent of the damage but there are strong suggestions he will miss the remainder of the Finals.
Controversially, the home fans in Toronto cheered as their opponent’s key player was withdrawn.
Warriors centre Draymond Green blasted the reaction as “classless” while Steph Curry criticised the “ugliness” of the crowd.
“[I’m] very confused around that reaction,” Curry said.
“You understand that this is about an individual and human being and not, oh shoot, he’s out, he’s hurt, we won the Championship.
“That was probably their initial thought and…you hate to see that when a guy’s going through pain like that.
“Again, that’s not my experience with this city and I just hope that that ugliness doesn’t show itself again as we go forward in the series.”
The Raptors had the opportunity to take advantage of the Warriors’ demise and they were in touching distance of the title.
With three minutes left on the clock, Nurse called for a timeout so his key men, such as Kawhi Leonard, could take a breather for the final push.
But those two-minutes also gave the Warriors time to regroup and they launched a late attack to overturn the six-point deficit to win the match.
Supporters and pundits alike have criticised the Raptors boss for getting the crucial decision wrong.
Nurse revealed in his post-match press conference the exact reason why.
“The two [minute break] we took at the three-minute mark, we had two free ones you lose under the three-minute mark,” Nurse said.
“We came across and decided to give those guys a rest. We thought we could use the extra energy push.”
Game six of the Finals gets underway on Thursday night in northern California.
And the Warriors will be hoping Green keeps himself out of trouble as he picked up a sixth post-season technical during last night’s victory.
It means one more issue in the upcoming tie could see him sitting out of any potential decider.