MARSEILLE, France (AP) -- Third-seeded Ernests Gulbis of Latvia reached the Open 13 quarterfinals on Thursday after a hard-fought 6-3, 5-7, 6-4 win against Roberto Bautista Agut of Spain, while fourth-seeded Andreas Seppi of Italy lost 7-6 (3), 6-4 to Michael Llodra of France.

Gulbis had 23 aces but needed more than two hours to win, while Seppi dropped his serve twice against Llodra, who had 14 aces.

Germany's Jan-Lennard Struff also secured an upset, beating seventh-seeded Julien Benneteau 4-6, 7-6 (3), 6-3.

Fifth-seeded Ivan Dodig of Croatia, No. 6 Edouard Roger-Vasselin of France, and No. 8 Nicolas Mahut of France progressed.

Dodig beat Germany's Tobias Kamke 6-7 (4), 6-0, 6-3, Roger-Vasselin advanced with a 7-6 (2), 6-4 win against Sergiy Stakhovsky of Ukraine, and Mahut won 7-6 (5), 6-3 against Ricardas Berankis of Lithuania.

Copyright 2014 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

SI Apps
We've Got Apps Too
Get expert analysis, unrivaled access, and the award-winning storytelling only SI can provide - from Peter King, Tom Verducci, Lee Jenkins, Seth Davis, and more - delivered straight to you, along with up-to-the-minute news and live scores.