We've had a big turn of events in the final round of the John Deere Classic. Zach Johnson now owns a one-stroke lead at 19 under through 16 holes. Johnson birdied Nos. 13 and 14 before making pars on 15 and 16. Troy Matteson just made a double-bogey 6 on the 15th hole to fall one shot back. Matteson missed the green left, fluffed his chip and then missed a 6-footer for bogey. He is now at 18 under, tied with Scott Piercy and John Senden. The reachable par-5 17th and the dangerous par-4 18th will determine the tournament. Should be fun to watch!