Justin Thomas equalled the course record to take a three-shot lead after the opening round at the RBC Heritage. Thomas made 11 birdies in a 10-under-par 61 at Harbour Town Golf Links in South Carolina.

At 10 under, Thomas commands a three-stroke lead over world No. 1 Scottie Scheffler and Arnold Palmer Invitational winner Russell Henley. Battling a bad back, former U.S. Open champion Wyndham Clark impressed in the early afternoon hours with a 65 of his own to stand four adrift.

In Thursday's first round of the RBC Heritage, Thomas fired a 10-under-par 61 at Harbour Town Golf Links, which ties the lowest professional score at the course, which has hosted the PGA Tour since 1969.