WASHINGTON (AFP) - Robert Streb piled up nine birdies in a nine-under-par 63 on Friday (Nov 20) to take a two-shot halfway lead over Camilo Villegas in search of his second US PGA Tour title at Sea Island, Georgia.

Streb fired a 63 on the par-72 Plantation Course, one of two in use in the first two rounds of the RSM Classic.

The layout didn't feature when Streb won his only prior US PGA Tour title at Sea Island in 2015, but the American looked right at home as Thursday's blustery winds gave way to balmy weather.

"Conditions were a little nicer," said Streb, ranked 380th in the world. "Greens are really good. If you're playing well, you can get it."

Streb led by four until Colombia's Villegas, who shared the overnight lead on six-under, eagled the par-five 18th on the Plantation course to cap a six-under 66 for a 12-under total of 130.

Villegas opened with back-to-back birdies and picked up another stroke at the seventh before his lone bogey at the 11th.

He followed another brace of birdies at 14 and 15 with his eagle at the last and was one stroke in front of Americans Bronson Burgoon and Patton Kizzire.

Burgoon also shot a 63 with nine birdies on the Plantation course, where Kizzire shot a six-under 66 to join him on 131.

All of the top seven, and nine of the top 10, played the Plantation on Friday, but all who made the cut will play the par-70 Seaside Course over the final two rounds at the weekend.

Villegas said a bit of luck at 18 helped him close the gap on Streb.

"I pushed my drive, it bounced on the cart path," he said. "I only had nine-iron in, so I was able to be a little more aggressive to a front pin that's in a tough place with the way it was playing downwind."

He said he enjoyed the weather that was "a little bit more Colombian" on Friday.

But Villegas, who won the most recent of his four US tour titles in 2014, cautioned that there was a long way to go before he could contemplate a return to the winner's circle in a season in which he has come back from a shoulder injury and also tried to cope with the death of his toddler daughter, Mia, from cancer in July.

Im misses cut

"We've only played 36 holes," Villegas said.

"I'm not going to say the confidence is coming back from these two past days, but I think having the shoulder good and all the work that I've put in the last few months made me feel better.

"It's not a two-day thing, it's a process. The swing feels good, the speed is better than it was and I'm pain free, so that's good."

Streb, too, said there was "a lot of golf left." (I'm) just trying to finish as well as I can and see if I can get in a better spot for the spring," he said.

The week was over for 22-year-old South Korean Im Sung-jae, who missed the cut a week after finishing with a share of second in his Masters debut at Augusta National.

Im followed a first-round 72 at Plantation with a one-under 69 at Seaside to miss the cut that came at three-under by two strokes.