Cousins, who has had verbal battles with Smart this season, entered the game at the start of the second quarter and finished with six points in nine minutes. He had started all 68 games he played this season.
"Am I surprised? Not at all," said Cousins, who said he found out at the morning shootaround. "It was his decision. He doesn't have to give me a reason, he's the coach."
And if Smart had a reason, he wasn't saying.
"I decided to go with the guys I had on the floor," Smart said. "There's no details and there's nothing behind it. I went with the guys that I thought at that particular time would give us what I was looking for with that team."
Vince Carter passed off to Wright early in second quarter for his 4,000th career assist. Carter, who had six assists in the first half, became the 15th player in NBA history to amass 22,000 points, 5,000 rebounds and 4,000 assists.
Carter, who had seven points and tied a season high with eight assists, said he had no idea he had entered such a select group.
"That's an honor. I'm not sure who is in the group, but I'm sure it's a lot of Hall of Famers," Carter said. "To get a milestone like that, it's a shock. To do that when we get a win is a great feeling."
Trailing by nine points entering the fourth quarter, the Kings went on a quick 9-2 run to close the gap to 94-90. After a timeout, the Mavericks responded, running off nine straight points for a 103-90 lead with 8:27 left.
"We were fine, we knew they were going to make a run," Wright said. "We did the things we needed to do to get this win."
After a huge second-quarter output, the Mavericks followed up with a strong third quarter. Marion scored mostly from close range on floaters and had 13 points in the third when the Mavericks built their lead to 92-81.
Nowitzki scored nine of his 11 first-half points in the second quarter, when the Mavericks outscored the Kings 41-26. Collison also had nine points in the second for Dallas, which took a 59-53 lead into the half.
Thomas had 15 points, Evans scored 11, and Thompson had nine points and 11 rebounds in the opening half for the Kings.
Notes: Kings forward John Salmons made a 3-pointer in the first quarter to break out of an extended scoreless streak. He had zero points in 38 minutes Wednesday against Houston and finished with three points in 25 minutes against Dallas. . Thomas ended the first quarter with a 15-foot floater at the buzzer that gave the Kings a 27-18 lead. . Mavericks veteran forward Elton Brand missed his second straight game with a sore right calf that has bothered him all week. . The Kings have lost four straight at home, where they own a 19-19 record.