Grigor Dimitrov had made it into the third round of the Monte Carlo Masters thanks to a three-set win over Spain's Albert Ramos.
The world number 14 lost the opening set 3-6, but he was able to restore parity in the second by taking it 6-3 after a single break of serve.
He then completed the turnaround as another break allowed him to serve out the contest 3-6 6-3 6-4 with just over two hours played.
Waiting for Dimitrov in the next round is Spanish sixth seed David Ferrer.