Zagreb, Croatia (SportsNetwork.com) - Second seed Adrian Mannarino was sent packing, while four other seeds, including Guillermo Garcia-Lopez and Andreas Seppi, posted second-round wins Thursday at the Zagreb Indoors tennis event.

Dutchman Igor Sijsling upset the Frenchman Mannarino in 7-6 (7-3), 4-6, 6-1 fashion at Dom Sportova, while the third-seeded Spaniard Garcia-Lopez grounded Bosnian Damir Dzumhur 6-1, 6-1 and the fifth-seeded Italian Seppi held off Brit James Ward 7-5, 6-7 (4-7), 6-3.

Seppi stunned Roger Federer in the third round at the Australian Open two weeks ago.

"I didn't have so much energy today," admitted Seppi on Thursday. "I felt a little bit down. I didn't feel I could play as aggressively as I wanted, and I gave him a little bit more space to play. I think he played really well. He served good at important moments. I could have actually finished in two sets as I was 7-5, 4-2 up, but I lost the tiebreak. Anyway, I am happy to be through and I will try to improve next match."

An upset came when Lithuanian Ricardas Berankis tackled fourth-seeded Gilles Muller of Luxembourg 3-6, 7-6 (7-5), 6-4, while seventh-seeded Serb Viktor Troicki avoided an upset by whipping Japanese Go Soeda 6-3, 6-1 on Day 4. The resurgent Troicki was a titlist in Sydney last month.

Troicki will meet Garcia-Lopez in Friday's quarterfinals, while Berankis will face Seppi.

Another result saw eighth-seeded Spaniard Marcel Granollers outlast Croatia's Ivan Dodig 7-6 (10-8), 4-6, 6-3. Dodig captured the title here in 2011.

Granollers will tangle with Sijsling on Friday.

The marquee quarterfinal will pit sixth-seeded 2012 Zagreb champ Mikhail Youzhny against former Australian Open runner-up and 2007 Zagreb titlist Marcos Baghdatis.

The 2015 Zagreb champ will collect $90,000.