Croat Ivan Dodig upset eighth-seeded Aussie round action at the $1.155 million Regions Morgan Keegan Championships.

Dodig blasted 19 aces and came from behind to stop the rising Tomic 5-7, 6-4, 7-6 (10-8) on the indoor hardcourts at The Racquet Club of Memphis.

In Monday's other first-round match, American Donald Young outlasted Bulgarian Grigor Dimitrov 7-6 (7-4), 4-6, 7-6 (8-6) in two hours, 23 minutes.

Young survived seven double faults, including one giving Dimitrov a free break while Young served for the match at 5-3 in the third.

Young will take on the winner of Wednesday's matchup between top-seeded American John Isner and Gilles Muller of Luxembourg. Dodig will face the victor of Denis Istomin-Jurgen Melzer. Istomin is Uzbekistani and Melzer hails from Austria.

The top seeds in Memphis are 6-foot-9 Isner, former world No. 1 American Andy Roddick, Czech Radek Stepanek and last week's San Jose winner Milos Raonic of Canada. Roddick beat Raonic in last year's Memphis finale to capture the title here for a third time.

The 2012 Memphis champ will pocket $277,915.