Unlike the first, this one paid off with a win.
And the Miami Heat are two victories from their first trip to the NBA finals since 2006.
Bosh scored 34 points, LeBron James finished with 22 points and 10 assists, and the Heat remained unbeaten at home in the postseason by beating the Bulls 96-85 in Game 3 of the Eastern Conference finals on Sunday night.
Dwyane Wade added 17 points and nine rebounds for Miami, which is now 7-0 at home and handed the team that finished with the NBA's best record its first losing streak since Feb. 5-7. Udonis Haslem sealed it with a jumper with 1:29 left, putting Miami up 93-84.
Bosh scored 30 points in Game 1 against Chicago, a game where Miami was embarrassed 103-82. The Heat haven't lost since, and only trailed for 3:22 in Game 3.
"I just wanted to be aggressive and just have some kind of imprint on this series," said Bosh, who's in the conference final round for the first time. "I had an aggressive Game 1, Game 2 was so-so, but we still won. But out here on the home floor I just wanted to be aggressive and it turned out to be a good game."
A really good game - it was five points shy of his postseason career best.
Carlos Boozer finished with 26 points and 17 rebounds for Chicago, which had won the first four meetings of the season with Miami.
Derrick Rose finished with 20 points, but struggled from the field once again, making only 8 of his 19 shots.
Taj Gibson had 11 off the Chicago bench.
Boozer made a pair of free throws with 6:39 left to get Chicago within 78-74, the outcome clearly hanging in the balance. Minutes later, that was no longer the case - not after Miami scored nine straight to build more than enough of a cushion.
Bosh and Boozer exchanged words and looks more than once on Sunday night, but Bosh ended up with the upper hand.
"All I care about is winning games," Bosh said. "And we do whatever it takes to get that."
How good was Miami's defense down that stretch? Bulls center Joakim Noah tried a 5-footer with 4:25 left. He shot it over the backboard.
Game 4 is Tuesday night in Miami.
Predictably, given the scene and the stakes, there was an abundance of energy from tip-off.
James, Wade and Rose all tumbled into courtside photographers while trying to make plays in the first five minutes, and Haslem was greeted by a huge roar when he entered - his first home appearance since Nov. 19 - later in the opening period.
Eventually, the emotional swings calmed down, and offense picked up in the second quarter.
Bosh was 5 for 5 in the second quarter on his way to a game-high 16 points by halftime. Boozer only missed one of his five shots in the second period, after going 0 for 5 to begin the game.
As for the past two NBA MVPs, everything was a battle.
Rose finished the first half with no assists, just the 11th time in his career that's happened. He did have 11 points by intermission, when Miami led 43-40 - meaning it held Chicago to 69 points in a 48-minute span dating to the midpoint of Game 2.
And James, who was the MVP in 2009 and 2010 before Rose took the trophy this season, was only 3 for 8 in the first three quarters. He did have 10 assists by the end of the third, though Miami let what was its biggest lead slip a bit in the final moments of that period.
Miami pushed the lead to nine late in the third on a jumper by Haslem, then saw most of that edge disappear quickly. Deng made a 3-pointer to get Chicago within 68-65, then stole Mike Miller's inbounds pass with 5.2 seconds left and got a good look at a jumper that rimmed out with a second left.
"That's obviously not the way we want to finish the quarter," Heat coach Erik Spoelstra said.
The fourth quarter, that was different. And against the NBA's top defensive team all season, Miami scored 53 points after halftime.