Nadal reaches US Open quarterfinals, will face Thiem
He had won six of seven meetings against Thiem, including all six on hard courts. Thiem's only victory had come on clay, his best surface.
But Anderson couldn't get anything going in this matchup with Thiem, who won 41 of 45 points (91 percent) and never faced a break point.
"First of all, I served really, really well today," Thiem said. "Not the best percentage, but I almost made every point in the first serve game. So I didn't face one break point, and I didn't feel so much pressure on service games."
Thiem reached his first quarterfinal at any Grand Slam besides the French Open. He was agonizingly close to getting there last year at the US Open, leading by two sets against Juan Martin del Potro in the round of 16 before the 2009 champion roared back to win.
"It was not on my mind, but I was pretty close last year," Thiem said. "It was very painful."Del Potro was on Sunday's night schedule, facing Borna Coric. John Isner or Milos Raonic would meet the winner of that match.
AP