By SCHUYLER DIXON
AP Sports Writer
McKINNEY, Texas (AP) — Sebastián Muñoz is atop the leaderboard again at the Byron Nelson after shooting 66. The Colombian who calls the Dallas area home will be joined in the final group Sunday by Jordan Spieth. The hometown favorite shot 8-under 64 and is one stroke back. Joaquin Niemann is another shot back in third. Spieth is a year younger than Muñoz at 28 but has three majors among 13 career victories. Muñoz is 2 1/2 years removed from his lone PGA Tour win.