PGA Tour rookie Steve LeBrun is one of three Americans tied for the second-round lead at the RBC Heritage on Friday. LeBrun carded a three-under-par 68 to join Kevin Streelman and Charley Hoffman in a share of the lead at six-under overall. Englishman Brian Davis, the overnight leader, struggled his way to a four-over 75 on day two at the Harbour Town Golf Links, South Carolina, dropping back to tied 25th at two under. World number six Luke Donald took over from his compatriot as the best-placed non-American on the leaderboard, matching LeBurn&aposs 68 to join Bill Haas in a tie for fourth at five under. A group of seven players are just two shots off the lead, with Americans Johnson Wagner and Pat Perez, South African Rory Sabbatini, Graeme McDowell of Northern Ireland, South Korean DH Lee and Australian pair Stuart Appleby and Marc Leishman all at four under. And there is no shortage of star power among those players tied for 13th, with the likes of German Martin Kaymer, Tim Clark of South Africa, Colombian Camilo Villegas and Americans Webb Simpson and Stewart Cink all three under. Villegas, even par through 17 holes, is one of several players yet to complete their second round, which was postponed due to inclement weather. Australian Jason Day had been second after Thursday&aposs opening round, but a two-over second round of 72 left him level with Davis and 11 others. Japan&aposs Ryo Ishikawa and American Jason Dufer also hold a share of 25th. Of the other Australians in the field, Cameron Percy is tied 38th at one under, while Aaron Baddeley and Matt Jones are tied 51st, level par for the tournament. Steven Bowditch, Alistair Presnell, Robert Allenby, Scott Gardiner and Daniel Nisbet all look set to miss the cut, and Greg Chalmers withdrew following his first round.