The American no.1 got to the quarters overcoming some problems against Pospisil.
The match lasted 1 hour and 48 minutes after Big Jiohny won 7-6 (3) 2-6 6-3. As usual the serve played a big role for Isner that blasted 14 aces on 14 service games to win 77% of the points on his first set.
“It was pretty ugly there for two sets but in the third set, I thought I played very well and it just turned around like that,” Isner said.
“That’s how I should play. I played aggressive, I was hitting my returns deep, I was coming in, I was making him win points with good shots. I wasn’t beating myself out there,”
In the other matches, Haas defeated Levine 6-3 6-1, Russell downed fellow countryman Donald Young 6-3 7-5.
Karlovic lost to Wildcard Steve Johnson 6-7 (2) 6-4 7-6 (6).
