Smart erupted for a career-high 39 points Tuesday in No. 7 Oklahoma State's 101-80 victory over No. 11 Memphis in Stillwater, Okla., prompting Durant to say that the star sophomore could play in the NBA "right now."
"Marcus can play in the league right now. Definitely," Durant, who attended the game at Gallagher-Iba Arena, told USA Today Sports.
Durant was one of many basketball fans across the country interested to see Smart's return to the national stage after he bypassed the NBA draft following the Cowboys' early exit from last season's NCAA tournament.
"We saw Kevin Durant, and we just wanted to go out there and put on a show," Smart said.
Durant, who has led the NBA in scoring three times, was impressed with Smart's all-around ability.
"He was just unbelievable for them tonight," Durant told USA Today Sports. "He was doing it all for them, rebounding, blocking shots, passing, scoring. He led them.
"I knew he could do everything pretty well. But I like his demeanor. I like how he handles his teammates. A player like him, he always can burst out and get 30 or 40 points."
The Oklahoma City Thunder star also said that Smart's decision to return for his sophomore season could prove beneficial.
"He is poised," Durant said. "And the extra year will help him out as far as knowing the game more. I wish him good luck."
In front of Durant, a host of NBA scouts and Oklahoma City coach Scott Brooks, Smart scored 26 points in the first half. He finished 11-of-21 from the floor and hit five 3-pointers while easily passing his previous career high of 28 points, set last season against Oklahoma.
"I was just feeling it tonight," Smart said. "My teammates found me and gave me the ball at times when I needed it in order to get my shot off."
"When [Smart] scores like that, he could be the best player in college basketball," Memphis coach Josh Pastner said.
Smart, who averaged 15.4 points and 5.8 rebounds as a freshman last season, currently is the No. 5 overall player on ESPN NBA Insider Chad Ford's latest draft Big Board.
Information from The Associated Press was used in this report.