World number one Novak Djokovic came from a set down to book a place in the quarter-final spot of the Monte Carlo Masters.
Djokovic pulled through against Juan Monaco to join third seed Rafael Nadal, who beat Philipp Kohlschreiber in straight sets.
Serb Djokovic was forced to come from behind for the second day in a row and credited his "inner strength" after beating Monaco 4-6 6-2 6-2.
Djokovic, who had been tested by Mikhail Youzhny in the second round, lost serve four times as he battled past Monaco in just over two hours to book a tie against Finn Jarkko Nieminen, Juan Martin Del Potro's conqueror.
It is his first clay-court tournament of the year and comes less than a fortnight after he twisted his ankle during a Davis Cup tie against the United States.
Sixth seed Jo-Wilfried Tsonga breezed past Jurgen Melzer 6-3 6-0 and he will now play Stanislas Wawrinka, who beat Andy Murray on Thursday.
Rafael Nadal's bid for a ninth successive Monte Carlo Masters crown remained on track as the third seed swept into the last eight by defeating Philipp Kohlschreiber.
Nadal was rarely troubled by the German, turning in a typically dominant clay court performance to see off the world number 21 6-2 6-4 in 81 minutes. He will next face Grigor Dimitrov, who continued his improved form of late with a 6-2 6-4 defeat of Florian Mayer.
Fourth seed Tomas Berdych was surprisingly ousted 6-4 6-2 by Italian Fabio Fognini and he was followed by Del Potro, beaten 6-4 4-6 7-6 (7/4) by Jarkko Nieminen in two hours and 38 minutes.
Nieminen missed a match point at 4-5 in the third set, but broke for a 6-4 lead in the deciding tie-break and closed out victory as del Potro hit a forehand wide. France's Richard Gasquet advanced to the quarter-finals with a 7-5 6-4 victory over ninth seed Marin Cilic.