By Chris Dunham, PGATOUR.COM ST. SIMONS ISLAND, Ga. -- The season of unpredictability on the PGA TOUR continues today on St. Simons Island. The final pairing at the McGladrey Classic tees off at 1:15 p.m. ET and features two 2010 q-school graduates and PGA TOUR rookies, both looking for their first TOUR victory and job security for next season. Michael Thompson, an Alabama graduate and last year’s Hooters Tour Player of the Year, is in sole possession of the lead at 13 under. One back is former Florida Gator Billy Horschel, a 2009 and 2010 q-school graduate who lost most of his 2009 season because of a wrist injury and retained rookie status this season. The two former SEC champions renew their rivalry for the second straight day at Sea Island. “I’ve played with (Billy) a couple times during college and I’ve played with him once this year,” Thompson said. “Billy and I have a lot in common… We’re just two young guys having a great time on the PGA TOUR.” Thompson trailed Horschel by one shot prior to the third round, but had three birdies on his front nine and parred his final nine holes Saturday to take a one-shot lead. “I know how to think now, in the final group on the weekend,” Thompson said. “Whether I have the lead or not, it really doesn’t matter. I’m just going to go out and play my game and add up the score at the end. Hopefully I’ll be the top guy.” After a pair of 64s to open the week, Horschel, who entered the week at No. 139 on the money list, never got on track Saturday, posting an even-par 70 to stay at 12 under through 54 holes. “I couldn’t win on Saturday,” Horschel said. “No one can ever win on Saturday unless there’s a storm coming in on Sunday and just washes the thing out. So obviously being one back of the lead going into the final round, I’ll take it. It would have been nice to be one ahead, but to be in contention going into the last day, I’ll take it.” The rookies will have some tough pursuers starting at 11 under in the next-to-last group: Trevor Immelman and Webb Simpson. Immelman, the 2008 Masters Champion who hasn’t had a full healthy season since 2006, tied a tournament record with an 8-under 62 Saturday to get within two shots of the lead. Simpson, who is trying to move ahead of Luke Donald for the top spot on the PGA TOUR money list, hit 13 fairways and 17 greens Saturday, but couldn’t get the birdie putts to drop in a 1-under 69. “I’m excited,” Simpson said after Saturday’s third round. “I looked at the board, and the guys are honestly playing well, but we’re well within reach. The only goal for today was to keep myself in the golf tournament and try to have a chance to win tomorrow, and I think we did that.” A victory for Simpson would be his third of the year and not only move him atop the money list, but improve his chances at winning the PGA TOUR Player of the Year award. Also in contention, and just four shots off the pace are Jeff Overton, Kris Blanks and Nick O’Hern, at trio of players in search of their first TOUR victories. Also in that group at 9 under is 2010 British Open champion Louis Oosthuizen, who is in search of his first win in the U.S. Barring an Immelman-like round from anyone in that group, they’ll need help from the final pairing, which will have control of how this final round shapes up. Quick starts from Horschel and Thompson could make it a two- or three-man race while a sluggish opening can bring as many as a dozen guys into the fold as potential winners. “I’m in a good position,” Horschel said. “If I just shoot a low number and give myself a chance, who knows what happens.” In this season of unpredictability, what happens today at Sea Island is anyone’s guess.