Milos Raonic withdraws to hand Jack Sock Delray Beach Open title

Raonic pulled out of the final due to a hamstring tear in his right leg

Sock is expected to rise to 18th in the world (Icon Sportswire via Getty)

Canadian world number four Milos Raonic pulled out of Sunday's Delray Beach Open final in Florida, handing American Jack Sock the title by walkover.

Raonic withdrew due to a hamstring tear in his right leg, an injury he said he had picked up while beating Argentine Juan Martin del Potro in straight sets in a semi-final on Saturday night.

"I didn't think much of it," Raonic told the Tennis Channel. "I thought it was just tightness from the match, but this morning I woke up unable to walk properly and did quite extensive treatment with my team.

"We came down to the conclusion that it was a slight tear of the hamstring in my right leg."

Sock's second ATP title of the year followed his Auckland Open victory last month.

The 24-year-old American did not drop a set all week. He has an 11-1 record this year and is expected to rise to 18th in the world rankings on Monday.