butler
Swingman Jimmy Butler has been a major asset for the Bulls in the playoffs. Reuters

A depleted Chicago Bulls dug deep for another impressive display of character and collective strength as they stunned defending NBA champions Miami Heat 93-86 in the opening game of their Eastern Conference semi-final series on Monday.

On the night when LeBron James was presented with his fourth Most Valuable Player award from league commissioner David Stern, it was instead the more modest but seemingly tireless talent of Chicago's Jimmy Butler which proved decisive.

Butler played all 48 minutes for the third straight game and scored 21 points, while grabbing 14 rebounds and three assists.

On top of that, in the absence of the ailing Luol Deng, Butler guarded James, restricting him to just two points in the first half, a post-season career low for the Miami forward.

Although James stepped it up after the break, finishing with 24 points on 8-of-17 shooting, Butler inspired the Bulls to a fourth quarter rally as they roared back from a seven-point deficit to grab the early advantage in the best-of-seven series.

"I like the mental toughness of this team," said Bulls head coach Tom Thibodeau, who was also unable to call on the services of injured Kirk Henrich and long-term absentee Derrick Rose.

"When you are facing adversity, you have to be mentally tough. But this is just one game. We are going to have to play much better in the next one," he added.

Butler, who came into the contest after playing every minute in Game Six and Saturday's Game Seven series decider against the Brooklyn Nets, epitomized that spirit.

"He is a tough kid," Thibodeau said. "He is mentally tough and that is what we need him to do right now. We're short-handed. We have a number of guys playing big minutes and that is what we need."

RUSTY HEAT

Miami's Dwyane Wade, returning from a knee injury which kept him out of Game Four of the series sweep over Milwaukee was impressed with the 23-year-old Butler, who is playing like a veteran in just his second year in the league.

"Jimmy is turning out to be a really good NBA player earlier in his career than some people expected. I think he is better than a lot of people think," he said.

Despite being the most dominant team in the NBA this season, the Heat suffered from what their fans had feared after seven full days of rest - rustiness.

Sweeping the Bucks earned the Heat that week off, while the Bulls were fighting past Brooklyn, and the unusually long break carried the danger of Miami losing their edge.

That certainly looked the case in the first half with Miami failing to make the most of their opportunities, but coach Erik Spoelstra was more concerned with the way his team lost the fourth quarter 35-24.

"We are not making any excuses for time off or anything else. With 35 points in the fourth quarter you are not going to win games in the playoffs giving that amount. We didn't close out the game in the way we are capable of," he said.

"This is going to be about who is going to impose their identity on the other team. They imposed their identity in this first game, no question. We did not," he added.

The defeat ended the Heat's franchise record-tying eight game post-season winning streak and was their second loss to Chicago at home this season.

Nate Robinson top scored for the Bulls with 27 points and the former New York Knicks and Boston Celtics guard said there was a unique team spirit to the current Chicago team.

"There is something special about this group. I don't know what it is but it just feels like we have been playing together for ten years - we just love to play for each other," he said.

The series continues with Game Two in Miami on Wednesday.

(Reuters - Simon Evans)