Milos Raonic rolls in first-round match at Delray Beach

Top-seeded Canadian Milos Raonic didn't show much rust on Tuesday en route to winning his first-round match in the Delray Beach Open with a 6-1, 6-4 victory over American qualifier Tim Smyczek in Delray Beach, Fla.

Raonic, who is ranked No. 4 in the world, recorded 10 aces and won 90 percent of his points off first serves in his first match since bowing out of the quarterfinals at the Australian Open.

"Overall I have to be happy," Raonic said. "I haven't played much tennis over the last few weeks, and I really put in as much work as I could over the last week to get into my best shape here, and now I'm here. I've won my first match and I hope I can continue. I feel good."

Raonic needed just 24 minutes to clinch the opening set and saved four break points to begin the second. Raonic survived a brief rally by Smyczek to advance to the second round to face Croatian Borna Coric, who posted a 6-2, 6-3 triumph over Colombian Santiago Giraldo.

Also on Tuesday, third-seeded American Jack Sock recorded a 6-4, 7-6 (2) victory over Moldova's Radu Albot. Sock, who secured his second singles title at the ASB Classic in Auckland, New Zealand last month, admitted he's feeling comfortable playing at the tournament.

"It's probably my eighth time playing here if you count the juniors. I have a lot of experience in Delray. I've played the junior clays here numerous times. So I have great memories here," Sock said. "I feel a lot more confident this year, a lot stronger, excited to be back and hopefully for many more years."

Sock advanced to face Spaniard Guillermo Garcia-Lopez, who cruised to a 6-3, 6-3 win over German Dustin Brown.

American Donald Young pulled off the upset of the day by outlasting second-seeded Croatian Ivo Karlovic, 7-6 (5), 7-6 (3).

German Steve Darcis also scored a surprise victory with a 3-6, 6-1, 6-4 triumph over sixth-seeded Australian Bernard Tomic.

Fifth-seeded Steve Johnson had a much easier time of it with a 6-1, 6-4 win over fellow American Stefan Kozlov. Seventh-seeded Juan Martin del Potro of Argentina never lost his serve in a 6-4, 6-4 victory over South Africa's Kevin Anderson.

Bosnia and Herzegovina's Damir Dzumhur and Coric earned straight-set victories on Tuesday while American Jared Donaldson required three sets to advance.