David Ferrer overcame a scare to progress to the third round of the Western & Southern Open with a 7-6 (7-5) 3-6 6-4 win over Ryan Harrison in Cincinnati.
Home hope Harrison showed plenty of fighting qualities to save 16 of the 19 break points he faced and take the second set in impressive fashion, but his Spanish opponent proved too strong in the end.
Third seed Ferrer needed two hours and 42 minutes to complete the three-set victory and book a last-16 clash with either Dmitry Tursunov or James Blake.
The first set was decided in a tie-break after neither opponent dropped their serve, with a combined total of 15 break-point opportunities going missing.
The second set was more one-sided as Harrison broke early and held his nerve to level things up despite facing four break points.
Ferrer was still not at his best in the final set as he continued to commit unforced errors and was broken twice, but he still managed to get over the line.
Harrison, who has been given a wild card into the US Open, said after the match: "I just wish I had served a little better. Obviously, I had some chances.
"I feel like my game is right there on the brink of playing those top guys. That's kind of where you want it.
"Obviously, it would have been great to get a win today, but I know that, going in, if I compete the way I can and play the way I'm capable of, I'm going to be able to challenge just about anybody."
Elsewhere in second-round action, Grigor Dimitrov recorded a comfortable 6-3 6-2 victory over beat Brian Baker, Julien Benneteau saw off Radek Stepanek 6-2 5-7 7-6 (7-4) while Roger Federer made a positive start to his hardcourt season with straightforward 6-3 7-6 (9-7) win over Phillip Kohlschreiber.
In the first round, ninth seed Stanislas Wawrinka claimed a 6-3 6-4 victory over Andreas Seppi, while No 11 seed Tommy Hass beat Kevin Anderson 6-4 6-4.
American John Isner gave the home fans something to cheer about as he saw off Florian Mayer 6-3 6-4. French No 15 seed Gilles Simon retired while a set down to Rogers Cup semi-finalist Vasek Pospisil.