BERLIN — Australia's Sam Groth pulled off a second-round shock at the Stuttgart grass-court tournament Wednesday by recovering from losing the first set to beat third-seed Feliciano Lopez in reaching the quarterfinals. The 27-year-old from Melbourne, who is ranked 66 in the world, dug deep to claim a 3-6, 7-6 (7-5), 7-6 (8-6) win over the Spaniard, who is 14th in the ATP rankings, having held his nerve in a desperately tight third-set. Groth has the chance to claim another scalp when he faces Serbia's Viktor Troicki in the quarterfinals. Eighth seed Troicki needed three sets and exactly two hours to also reach the last eight as he saw off 18-year-old German Alexander Zverev, the youngest player in the top 100, 6-3, 6-7 (6-8), 6-3. Fourth seed Gael Monfils needed two tie-breakers to force his way into the quarterfinals with a over Austria's Andreas Haider-Maurer. Monfils took nearly an hour-and-a-half to seal his 7-6 (8-6), 7-6 (7-5) win and will now face either Poland's Jerzy Janowicz or home favorite Philipp Kohlschreiber for a semifinal place. Monfils said that he is under pressure from his fitness trainer to win a first grass-court title, particularly as there is a new Mercedes on offer to the winner. "He's in love with the car. He's been talking about it for two days," said Monfils, who sent down 18 aces. "He said: 'I don't care if you're not a grass-court player, you need to win this car for me! So make the effort!' I've won my first match so hopefully I can keep it going and get this car. " Top seed Rafael Nadal starts his campaign Thursday with a second-round match against Marcos Baghdatis. Karlovic in quarterfinals In the Netherlands, fifth-seeded Ivo Karlovic of Croatia smacked 25 aces as he beat Tatsuma Ito of Japan 7-6 (5), 7-6 (3) to reach the Topshelf Open quarterfinals Wednesday. There, he'll face local favorite Robin Haase, who beat seventh-seeded Fernando Verdasco of Spain 7-6 (4), 6-3. Verdasco had 10 aces, but lost the only service game of the second-round match. In women's play, third-seeded Coco Vandeweghe of the United States; No. 5 Camila Giorgi of Italy, and No. 7 Kristina Mladenovic of France reached the last eight. Vandeweghe won 7-5, 6-4 against Tatjana Maria; Mladenovic rallied past Kurumi Nara 6-7 (4), 6-3, 6-3, and Giorgi withstood 21 aces from Michaella Krajicek in a 6-7 (2), 6-2, 6-4 win. Yaroslava Shvedova of Kazakhstan, who eliminated top-seeded Eugenie Bouchard in the first round, beat Marina Erakovic of New Zealand 6-4, 6-4. — Agencies
