PALM HARBOR, Florida - Adam Scott has charged into contention at the US PGA's Tampa Bay Championship, but American rookie Shawn Stefani is clinging to a one-shot halfway lead over the Australian No.1 and and South Korea's KJ Choi.
Scott fired a bogey-free round of five-under 66 and Choi opened with an eagle on his way to a 67, but Stefani's 70 was enough to keep him ahead at seven-under at the $US5.5 million ($A5.32 million) event.
Scott and Choi share second at six-under with Americans Brian Harman, Harris English, Jason Dufner and Peter Tomasulo another stroke off the pace and Spain's Sergio Garcia and American Tag Ridings sharing eighth a further stroke adrift.
Scott, coming off a share of third last week at Doral, birdied all four par-5 holes on the Innisbrook Copperhead layout - the first, fifth, 11th and 14th - and birdied the par-three fourth as well.
"To go bogey-free anywhere is good, Here is particularly good," Scott said