They shot just 36 percent and were 6 of 18 on 3-pointers. They were also missing Kirk Hinrich, who sat out with back stiffness.
"Losing (stinks), there's no question about it," Noah said. "But it also shows true colors, who's willing to keep fighting through the adversity or who's just going to say, 'You know what, I want no part of this. I'm just going to take bad shots and just not care at all about making winning plays, playing defense, things like that.'"
The Raptors led 51-41 at the half after Lowry nailed a 20-foot jumper and open 3-pointer in the closing seconds, and they scored the first six of the third quarter, with the Bulls turning it over twice and missing four shots.
Johnson's jumper made it 57-41 three minutes into the quarter, but Bulls started to chip away.
Marquis Teague banked in a 3 in the closing minute of the third to make it 73-66, and D.J. Augustin hit one early in the fourth to make it a four-point game.
The Bulls saw their championship visions get crushed when they lost Derrick Rose to another knee injury. Just about every other key player has been banged up, too.
"I think a lot of it is us having guys in and out," Deng said, referring to the Bulls' struggles on offense. "We're not getting as much practice time with guys."
But Noah didn't want to go down that route.
"No excuses," he said. "I know that we're capable of a lot better than that. We can't get frustrated. Our effort has to be a lot better to play winning basketball. But it's going to come."
The Raptors seem to be coming together after experiencing some upheaval the past week.
They acquired point guard Vasquez and forwards Patrick Patterson, John Salmons and Chuck Hayes along with financial flexibility after the season in the deal that sent Gay to Sacramento. They also waived Augustin, who was signed by Chicago.
"It's gone well," Patterson said. "We want to come in with the right mentality and attitude. What we bring individually we want to incorporate in the system. I think we've done that. Moving the ball, sharing the ball, making the extra pass, averaging high assists every night, that causes everybody to have fun. No one is being selfish.
"That'll make everybody want to play tougher than before."
Casey said Augustin could fill a need for Chicago, something he was unable to do in Toronto. "We had a gluttony," he said. "Kyle Lowry was getting a lot of minutes." Signed as a free agent in July, he appeared in 10 games this year with the Raptors and averaged 2.1 points and 1.0 assists for Toronto. ... Hinrich missed his first game this season.