The 53-year-old Mediate opened with a 62 on Thursday to tie the tournament and course records set by Kenny Perry in the 2012 final round on the Jack Nicklaus-designed layout. On Friday, Mediate started play on the 10th tee and birdied the par-4 16th and 18th. He added birdies on the par-5 fifth, par-4 eighth and par-5 ninth, leaving an eagle putt an inch short on the last.
Mediate had a 14-under 128 total. He has two PGA Tour Champions victories after winning six times on the PGA Tour.
Gene Sauers was second, closing with a bogey for a 69.
Bernhard Langer birdied three of his last four holes in a 64 to reach 9 under in his bid to become the first player to win all Five PGA Tour Champions majors. The 58-year-old German won the Regions Tradition last week in Alabama for his sixth senior major title and 100th worldwide victory. Two-time defending champion Colin Montgomerie (66) and club pro John DalCorobbo (68) also were 9 under.
Lone Oak alum Kenny Perry shot a second round 71 Friday and is tied for 13th at 6 under. John Daly missed the cut with rounds of 75 and 74.
