Legendary NBA commentator Walt Frazier has described Dante Exum’s professional debut in Las Vegas as impressive.

Dante Exum has begun his NBA career with a couple of high-flying dunks and other flashes of brilliance.

The 18-year-old from Melbourne, playing against the Philadelphia 76ers at the NBA Summer League in Las Vegas on Saturday, took less than three minutes to show why the Utah Jazz selected him with the fifth pick of the draft.

Exum pulled a lob pass from teammate Trey Burke out of the air for an alley-oop dunk.

Late in the second quarter Exum turned the ball over, stole it back and then slammed it again.

“I was nervous at the start, but it was just about getting out there and getting a run,” Exum said.

The Australian Institute of Sport graduate finished his first professional game with 10 points, three rebounds and three assists from 27 minutes on the court.

The Jazz lost 74-70, despite Exum hitting a three-pointer to draw the Jazz even at 68-68 with 90 seconds left.

The Summer League is a pre-season tournament allowing NBA teams to play their draft picks, free agents and bench players ahead of the start of the 2014/15 regular season in October.

While Exum has received loads of publicity, signed endorsement deals with adidas and Red Bull and starred in Foot Locker commercials on US TV, the game against the 76ers was the first time most American sports fans were able to see Exum play.

“A lot of people are questioning my ability to be here, but I’m here and I’m coming out on the court and showing it every night,” Exum said.

“I’m looking forward to getting back on the court and showing more.”

Exum received plenty of praise, particularly for his speed, passing and unselfish play.

“For a guy who is only 18-years-old, coming into this hostile environment, he was very impressive,” NBA legend Walt Frazier, a TV commentator at the game, said.

Another Australian on the Jazz Summer League squad, forward Brock Motum, who played in Italy with Virtus Bologna, did not hurt his chance of scoring an NBA contract with an explosive dunk off an Exum three-point miss to go with his four rebounds.

Queensland power forward Cameron Bairstow, drafted by the Chicago Bulls, had his professional debut in an 86-70 win over the Los Angeles Clippers.

Bairstow had eight points and six rebounds.

It wrapped up a big day for Australian basketball, with Patty Mills re-signing with the San Antonio Spurs in a three-year, $US12 million deal.

Exum, who turns 19 on Sunday, inked a $US3.615 million first-year contract on Friday.