Opelka stuns Anderson in Atlanta, Isner rolls on

It was a day to remember for American wild card Reilly Opelka, who rallied to stun third seed Kevin Anderson in the second round at the Atlanta Open.

Opelka fended off two match points as he sensationally progressed to the quarter-finals with a 6-7 (5-7) 6-3 7-5 win at the ATP 250 tournament on Wednesday.

The world number 556, who clocked up 20 aces, faced elimination on two occasions as Anderson served for the match at 5-4, but Opelka reeled off three consecutive games to triumph in two hours, 50 minutes.

It does not get any easier for the 18-year-old Opelka.

Standing in the way of Opelka and a semi-final berth is countryman and seventh seed Donald Young, who outlasted Tim Smyczek 4-6 7-6 (7-1) 6-3.

Top seed and three-time defending champion John Isner had no trouble against Adrian Mannarino, opening his Atlanta campaign with a straight-sets victory.

Isner won the last 10 games to dispose of Mannarino 6-4 6-0.

Big-serving American Isner trailed 4-2 in the opening set but he rallied to break twice, blitzing Mannarino for his 13th consecutive win in Atlanta.

In the last eight, Isner will face eighth seed Taylor Fritz, who prevailed 4-6 6-3 6-2 against fellow American Bjorn Fratangelo.