Cipolla needed just more than a hour to defeat Dolgopolov 6-4, 6-1. He lost just 13 points over his eight service games and didn't face a break point.
Cipolla dropped 13 points total in the second set when he won 68 percent of the points on serve and 65 percent when receiving.
Igor Andreev knocked off fourth-seeded Denis Istomin 6-7 (3-7), 6-3, 6-2. He controlled the third set, losing three points on serve and finishing off 2-of-3 break-point chances.
Also Wednesday, Benoit Paire outlasted Matthias Bachinger 6-7 (3-7), 6-3, 6-2 in a match that took more than 2 1/2 hours. There were a total of 31 break-point opportunities in the match but Paire was able to finish off two in the third set while not losing his serve.
Paire will go against Cipolla in the quarterfinals.