Metz - Second seed David Goffin eased into the ATP Metz Open quarter-finals but French third and fourth seeds Lucas Pouille and Gilles Simon were made to struggle on Thursday.Belgian Goffin, the world No 14, beat Jan-Lennard Struff of Germany 6-4, 6-2 in his second-round clash and will play France's Nicolas Mahut, who beat Illya Marchenko of Ukraine 6-3, 6-4, in Friday's quarter-finals.
Pouille, the world number 18, needed almost two hours to see off his world number 112 ranked compatriot Pierre-Hugues Herbert 6-4, 6-7, 6-4.
He next faces French wildcard and world No 233 Julien Benneteau.
Simon was also pushed to a decider by Spain's Guillermo Garcia-Lopez.
World No 28 Simon eventually prevailed 6-7, 6-3, 6-4 and will next face Tunisia's Malek Jaziri, who ousted Frenchman Vincent Millot 4-6, 6-3, 6-3.
ATP Metz Open second round results on Thursday (x denotes seeding):
Gilles Simon (FRA x4) bt Guillermo Garca-Lpez (ESP) 6-7 (5/7), 6-3, 6-4
Malek Jaziri (TUN) bt Vincent Millot (FRA) 4-6, 6-3, 6-3
Lucas Pouille (FRA) bt Pierre-Hugues Herbert (FRA) 6-4, 6-7 (6/8), 6-4
David Goffin (BEL x2) bt Jan-Lennard Struff (GER) 6-4, 6-2
Nicolas Mahut (FRA x8) bt Illya Marchenko (UKR) 6-3, 6-4