Croatia's Ivan Dodig and American Donald Young both had solids starts at the Regions Morgan Keegan Championships by winning their first round matches on Monday.
Dodig hammered 19 aces as he rallied to beat eighth-seeded Bernard Tomic of Australia 5-7, 6-4, 7-6 (10-8) at the $1.1 million men's and women's event at the Racquet Club of Memphis.
Young needed two hours and 23 minutes to defeat Bulgaria's Grigor Dimitrov 7-6 (7/4), 4-6, 7-6 (8/6). The 22-year-old Young won despite finishing with just one ace and seven double faults.
Dimitrov had six aces and won 67 percent of his first serve points but committed six double faults in a sloppily played match.
Young will next play the winner of a contest between top-seeded American John Isner and Gilles Muller of Luxembourg.
Dodig will face either Denis Istomin or Jurgen Melzer. Istomin reached the final of the San Jose Open last week.
No. 2 seed Andy Roddick is chasing his fourth title at the event. He beat Canada's Milos Raonic in last year's final 7-6 (9/7), 6-7 (11/13), 7-5.
Raonic will be seeking his second title in as many weeks after winning in San Jose on Sunday.
Fourth seeded Raonic, who was named the ATP Tour's Newcomer of the Year, is also trying to win his third title of 2012. He opened his season by capturing the Chennai crown in New Delhi, India.
Raonic faces Ernests Gulbis of Latvia in his first round match.
On the women's side, third seeded Czech Lucie Hradecka dominated Anna Tatishvili 6-3, 6-1 and fourth seeded Marina Erakovic of New Zealand came from behind to beat Sloane Stephens of the US 4-6, 6-0, 6-1 in first round matches.
Former champions of this event include Bjorn Borg, Jimmy Connors and Andre Agassi.