Top-ranked Novak Djokovic dug deep for the second match in a row to reach the semifinals of the Serbia Open with a 4-6, 6-3, 6-3 win over Miomir Kecmanovic.
Kecmanovic won the opening set without facing a breakpoint, but Djokovic finally showed signs of getting back to his best in the second and then won the final four games of the decider in what was just his sixth match of the year.
The 20-time Grand Slam champion stretched his winning streak against compatriots to 10 matches going back to a loss to Janko Tipsarevic in Madrid in 2012.
Djokovic next plays third-seeded Karen Khachanov, who defeated Brazilian qualifier Thiago Monteiro 7-5, 6-4.
Djokovic also endured a tough game Wednesday when he rallied from a set down to beat compatriot Laslo Djere 2-6, 7-6 (6), 7-6 (4).
He joked that he was happy he would not have to face another Serb in the semifinals.
Djokovic opened his clay-court season with a surprising loss to Alejandro Davidovich Fokina at the Monte Carlo Masters last week, his first match since being eliminated in the quarterfinals of the Dubai Tennis Championships in February.
Dubai was his first tournament of the year after he was barred from playing at the Australian Open because of his unvaccinated status, which also prevented him from playing tournaments in the United States last month.
Earlier Thursday, second-seeded Andrey Rublev defeated Jiri Lehecka 4-6, 7-6 (1), 6-2 and Fabio Fognini enjoyed a 6-2, 6-3 win over Aljaz Bedene to reach the quarterfinals.