Janko Tipsarevic could be in line meet fellow Serbian and world number one Novak Djokovic in the quarter-final of the US Open after a four-sets victory over Juan Carlos Ferrero.
In a closely fought match on the Louis Armstrong Stadium, Tipsarevic and Spaniard Ferrero shared the first two sets 7-5 7-6[7/3] respectively.
Number 20 seed Tipsarevic held his nerve in the third set, breaking his opponent late on to claim a 7-5 win.
Ferrero failed to recover and surrendered the fourth set to the 27-year-old 6-2.
Alexandr Dolgopolov stands in the way of an all-Serbian match in the final eight.