Shane Lowry was convinced his game was on the rise, despite his poor scoring, he finally showed that Thursday in the RBC Heritage, shooting a 6-under 65 to take a one-shot lead. Trey Mullinax, Daniel Berger, Luke List, Ryan Moore and Ryan Palmer were tied for second. Top-ranked Dustin Johnson, coming off a second-place tie at Masters last week, rallied with two birdies in his final seven holes for a 68, leaving him three shots back. Rory Sabbatini (67) joined a host of players two shots off the pace. Defending champion Satoshi Kodaira was at 2-over 73.