France\'s Gael Monfils admitted he was delighted by his form on the grasscourts of Halle\'s ATP tournament after booking his quarter-final berth with a straight sets win on Thursday. The 24-year-old third seed saw off Serbia\'s Ivan Dodig with a 6-2, 6-3 second round win and will now play either six-seeded German Florian Mayer or Taiwan\'s Yen-Hsun Lu, who meet later Thursday, in Friday\'s quarter-finals. Monfils conceded he was not a natural on grass and was looking to improve his game with Wimbledon now ten days away. \"I really feel good, especially because I moved well,\" said Monfils, who beat compatriot Florent Serra in straight sets in the first round here. \"I am happy about that, because I do have problems adjusting to grass. \"In the last ten days before Wimbledon, I want to improve my overall game further still - serve faster and stronger and work on my movement. \"Last year, I was terrible on grass, because that surface does not come natural to me, so this year I am happy, I want to continue improving. \"All in all, after this second easy win, I think I have made a good debut on grass here in Halle.\" Monfils says he is wary of a possible quarter-final clash with Lu, who upset Andy Roddick last year at Wimbledon on his way to the last eight. \"I don\'t have a preference who I want to play in the next round,\" he said. \"Florian Mayer is a tricky player and Lu plays very solid on Grass, he showed that last year when he beat Roddick in Wimbledon.\" Having beaten lucky loser Leonardo Mayer in the first round, defending champion Lleyton Hewitt is in action later on Thursday evening when he plays Italy\'s Andreas Seppi with a quarter-final place at stake.