Casablanca, Morocco (SportsNetwork.com) - No. 6 seed Andreas Haider-Maurer and former top-10 star Nicolas Almagro were among Tuesday's opening-round winners at the Grand Prix Hassan II tennis event.

The Austrian Haider-Maurer barely snuck past German Jan-Lennard Struff 6-2, 6-7 (0-7), 7-6 (7-5) in 2 hours, 33 minutes on the clay courts at Complexe Al Amal. Struff smacked 15 aces in a losing effort.

The wild card Almagro toyed with Japan's Taro Daniel, 6-4, 6-1, while Belgian qualifier Arthur De Greef, making his ATP debut, took out eighth-seeded Argentine Diego Schwartzman 4-6, 7-5, 6-4 on Day 2.

Meanwhile, Russian veteran Mikhail Youzhny whipped Moroccan wild card Yassine Idmbarek 6-3, 6-1; Spaniard Pablo Andujar, a back-to-back Casablanca champion in 2011 and 2012, handled German Tobias Kamke 6-3, 6-4; Bosnian Damir Dzumhur topped Frenchman Paul-Henri Mathieu 6-2, 7-6 (7-2); Moroccan wild card Lamine Ouahab drubbed Dutchman Robin Haase 6-2, 6-4; Spaniard Daniel Gimeno-Traver mauled Tunisian Malek Jaziri 6-4, 6-3; and Slovenian Aljaz Bedene held off Argentine Maximo Gonzalez 6-3, 3-6, 6-3.

This week's top seed is reigning champion Guillermo Garcia-Lopez, who topped Marcel Granollers in last year's all-Spanish final. Garcia-Lopez will face Ouahab on Thursday, while Granollers will battle Dzumhur on Wednesday.