John Isner powers way to Atlanta Open Final

Second seed Isner needed just 75 minutes to extend his spectacular success at the tournament. He lost to Australian Nick Kyrgios in last year's final but won the tournament in 2013, 2014 and 2015.

"It was a very good match. Absolutely nothing to complain about today," Isner told reporters. "I feel great physically, maybe the best I have felt in quite some time. More importantly than that I am pretty confident as well."

Isner will bid for his fourth Atlanta title on Sunday when he faces fourth-seeded American Ryan Harrison, who posted a 6-7 (5), 6-3, 6-4 victory over fifth-seeded Brit Kyle Edmund.

The 32-year-old Isner broke Muller in the third game of the first set to gain early advantage and twice in the second before erasing three break points while serving for the match.

"He made it very tough for me today," Muller said after dropping to 2-4 versus Isner in his career. (Writing by Jahmal Corner in Los Angeles; editing by Sudipto Ganguly)