Jason Day had himself a day. Day, one of the co-leaders after the opening round, shot a five-under 66 in Sunday's third round to take sole possession atop the leaderboard at the Deutsche Bank Championship at -17. Day's three-round score of 196 ties the 54-hole record at TPC Boston. The Australian leads American Brandt Snedeker by one stroke heading into Monday's final round, and a two-shot lead on Luke Donald. Steve Stricker, currently fourth in the World Golf Ranking, sits at 13-under, along with Charlie Hoffman. Noted golfing enthusiast Tiger Woods had another good round, going -3 on Sunday, and is now seven-under for the tournament, but 10-back from Day. Both Stricker and Phil Mickelson have the opportunity to overtake Woods for the No. 1 spot in the world rankings. Round four is underway at TPC Boston, with the final group set to tee off at 1:45 P.M. EDT. NBC's coverage begins at 2 P.M.