In Atlanta on March 3, the Chicago Bulls (39-24) lost to the Atlanta Hawks (30-32) in a high-scoring affair, 130-124.
For the Hawks, who are struggling for any spot in the playoffs, a win over the upper-tier Bulls was especially important, ESPN noted.
Chicago suffered its third consecutive loss and fell percentage points behind Philadelphia in the battle for second place in the East, with each now two and a half games behind Miami.
"We've got to have way, way better habits against elite teams," Chicago coach Billy Donovan said. "I think we're learning the tough way all these little lessons, so to speak. ... There was just a lot, a lot of breakdowns. We fouled entirely too much."
DeMar DeRozan led the Bulls with 22 points, eight assists and two steals. Trae Young had 39 points for the Hawks.
The Bulls next host defending NBA champions the Milwaukee Bucks on Friday, March 4, at the United Center.
In NHL action, the Chicago Blackhawks (20-27-8) edged the Edmonton Oilers (30-21-4) 4-3 in overtime at the United Center on March 3.
Sam Lafferty, Patrick Kane and Dominik Kubalik scored in regulation before Alex DeBrincat played overtime hero. Marc-Andre Fleury stopped 28 shots in his 17th win of the season.
Duncan Keith played in his first game back at the United Center since being acquired by the Oilers in July. Also, retired player Niklas Hjalmarsson was honored for his 14-season career, including 10 in Chicago.
The Blackhawks will next open a weekend back-to-back on Saturday, March 5, with the first meeting of the season against the Philadelphia Flyers before hosting the Tampa Bay Lightning on Sunday, March 6, at home.