Ivan Dodig of Croatia beat No. 8 seed Bernard Tomic of Australia 5-7, 6-4, 7-6 (8) on Monday in the opening round of the Regions Morgan Keegan Championships.
The unseeded Dodig survived two match points in a third-set tiebreaker, winning when Tomic netted an easy volley to end the nearly three-hour match.
"I was really happy after the match because I've been losing tight, tight matches," Dodig said. "This is going to give me more confidence."
American Donald Young also won, outlasting Grigor Dimitrov of Bulgaria, 7-6 (4), 4-6, 7-6 (6). Young, 22, survived a shaky outing in which he was broken five times and had seven double faults.
The 19-year-old Tomic, Australia's top-ranked player, lost for only the third time this season. His only other losses have been to third-ranked Roger Federer and No. 4 Andy Murray.
"Last year, he showed that he can play good tennis against great players and will soon be one of the top players in the world," Dodig said of Tomic. "This match, it was just a matter of a little bit of luck. I was a little more lucky in the tiebreaker."
American John Isner, the tournament's top seed, will play his first match on Tuesday against Gilles Muller. Isner is ranked a career-best 13th.
Second-seeded American Andy Roddick, the defending champion in Memphis, will play his first match onÂ Wednesday. The 29-year-old is 27th in the latest ATP rankings, his lowest position since August 2001.
Among those advancing to the second round in the Memphis International, the accompanying women's event, were No. 3 seed Lucie Hradecka of the Czech Republic, No. 4 seed Marina Erakovic of New Zealand and Michaella Krajicek of the Netherlands, who upset No. 6 seed Elena Baltacha of Britain 6-2, 6-1.
Sofia Arvidsson of Sweden, the 2006 Memphis champion, also won her first-round match, a 6-2, 6-3 victory over Heather Watson of Britain.
In a doubles exhibition, former world No. 1 John McEnroe, who turned 53 last week, teamed with 19-year-old Jack Sock to beat Sam Querrey and James Blake, 7-6 (5), 6-4.