Nicolas Kiefer, Nikolay Davydenko and Sebastien Grosjean all booked spots in the quarter-finals after a day of tough encounters at the Australian Open.
Both Kiefer and Grosjean managed to save important energy reserves with straight-set victories, while Davydenko battled through five sets to edge out Dominik Hrbaty in a gruelling match.
Kiefer had to toil hard for a tough 7-6 (7-4) 6-3 6-3 win over Argentinean Juan Ignacio Chela.
The German 21st seed turned on a strong performance to overcome his gritty competitor in straight sets.
Chela, who beat Britain's Andy Murray in the opening round and Australian hero Lleyton Hewitt in the second, played well but could not win the important points and that eventually proved fatal to his tournament hopes.
The opening set soon turned into a battle as neither player faltered during their own service game and with the score soon tied up at 6-6 the first set came down to a deciding tiebreaker.
Both players continued to battle hard but it was the German who managed to pull through, Keifer breaking his opponent’s serve twice in a row to claim the tiebreaker.
The second set proved to be one marred by errors from both players as five service games were broken in a row.
However, it was Keifer again who emerged on top, the German taking the upper hand in the seventh game of the set before easing through to win it.
The German then exacted the important break in the fourth game of the final set on the way to a 6-3 victory to book a spot in the quarter-finals.
Meanwhile, Davydenko had to battle back from two sets down to advance through to the quarter-finals after an energy-sapping 4-6 4-6 6-4 6-2 6-3 victory over Hrbaty.
The world number five turned on a mixed performance but came back beautifully to dispatch his Slovakian opponent in convincing style, the Russian taking well over three hours to seal the win.
Davydenko stamped his mark on the match purely by making fewer errors than Hrbaty, as powerful baseline hitting dominated the clash.
The match eventually proved to be too much for the Slovakian, who began to tire towards the end having already played three five-set matches on the way to the fourth round.
In the all-French affair it was the seeded Sebastien Grosjean who triumphed over compatriot Paul-Henri Mathieu.
The 25th seed was all class as he raced to a 7-5 6-2 6-2 victory over his less experienced opponent.
The first set proved to be a difficult one to claim as both players battled hard to hold their early service games.
However, it was Grosjean who finally found the important break as he took the first set 7-5.
This proved to be all the resistance Mathieu could muster as Grosjean soon found another break in the youngster’s faltering game, the second set soon won by the 25th seed. Grosjean again found important breaks on the way to a comfortable victory.