Jason Dufner seized a two-shot lead at the US PGA Tour\'s Transitions Championship as overnight leader Padraig Harrington failed to find the dazzling form he displayed just a day before. Harrington, who opened the tournament with a course-record 61 on Thursday, settled for a two-over par 73 on Friday to fall two shots behind Dufner, who carded a second successive 66 and has yet to make a bogey on the par-71 Copperhead Course at Innisbrook. Harrington, whose 22 putts on Thursday included a 75-footer, couldn\'t get the putts to drop on Friday. The three-time major champion missed four putts from within 10 feet, taking 33 putts overall. Dufner, seeking a first US PGA Tour title after 159 starts, had a 10-under total of 132. Harrington was on eight-under 134, where he was joined by William McGirt, who carded a 68. England\'s Luke Donald, who could regain the world number one ranking with a victory this week, posted a 68 to lead a group of five players on 135. He was joined by South Korea\'s Sang-Moon Bae (66), Ken Duke (67), Chris Couch (68) and George McNeill (68). It was a further shot back to Australian John Senden, Spain\'s Sergio Garcia, Jim Furyk and Kenny Perry were on 136.