SAN FRANCISCO (AFP) — World No. 1 Scottie Scheffler finished with back-to-back birdies to hold a share of the lead after the second round of the PGA Tour Pebble Beach Pro-Am on Friday.

Scheffler shot a bogey-free, eight-under-par round of 64 to share top spot on the leaderboard at 11-under with Belgian Thomas Detry and Sweden's Ludvig Aberg.

The American sank a 35-footer to make birdie on the par-3 17th and then followed up with an aggressive approach on the par-5 18th.

"Boring is always nice on the card, keeping a clean card is good," said Scheffler of his avoidance of bogeys on the historic Californian course.

"I felt like I didn't have to struggle for many pars. I kept the golf course in front of me, made some nice puts and hit some quality shots into the greens. I just gave myself a lot of opportunities," he said.

"I did not realize how much it rained overnight. It was really wet. So like on a lot of these back-to-front greens it's a big adjustment going from hitting a pitching wedge to hitting an 8-iron to try to take off spin."

The soft, wet course encouraged players to attack the greens and Aberg certainly took that approach, following up a birdie on the first with an eagle on the par-5 second.

After a thumping 302-yard drive, the 24-year-old landed his approach 35 feet from the hole and sank his putt superbly.

Aberg was outstanding on the greens as he reached the turn on five-under and he added two more birdies on the back nine on the 11th and 14th.

"Obviously, I got off to a nice start with a couple of long putts, I don't remember the last time I did that, so obviously that's a little bonus. I felt like I kept playing quite well and kept being disciplined, so it was nice," the Swede said.

Aberg, who played college golf in the USA for Texas Tech and turned pro in June, picked up his first win on the PGA Tour in November at the RSM Classic, following up his win on the DP World Tour in Switzerland in September.