Ryan Fox fired a 62 at Royal Birkdale on Saturday, becoming the third player this week to match the men's major-championship low round and moving within two shots of the lead entering Sunday.
Little wind and firm, fast links conditions fueled the scoring burst, with Fox making nine birdies and attacking with his driver and wedges during an early tee time.
Sam Burns still held first place at 10-under after a 65, while 36-hole leader Lucas Herbert slipped back with a 71 to sit three behind.
Royal Birkdale has now produced four of the eight 62s in major history, including Branden Grace's first record-setter in 2017, and is the first major venue to yield three rounds of 63 or lower in one championship.