Defending champion Ernests Gulbis and top seed Milos Raonic both crashed out on a day of upsets at the ATP Open 13.

Gulbis beat Jo-Wilfried Tsonga in last year's final, but was defeated 6-3 6-4 by another Frenchman, Jeremy Chardy, on Thursday.

In a tight contest, Chardy proved more clinical in taking his chances - never losing a game in which he forced a break point.

In fact, Chardy did not lose a single service game and staved off four break points on his way to victory.

The world number 35 will now face compatriot Gilles Simon in the quarter-finals.

Simon, champion in 2007, picked up a 6-2 3-6 6-3 victory over Borna Coric to book his place in the next round.

In the day's other big upset, Simone Bolelli ended the longest losing streak of the Open era against top-10 players with a 6-4 3-6 7-6 (7-3) win over Raonic.

Having lost his previous 35 encounters with players ranked in the world's top 10, Bolelli stole a march with a late break in the first set.

The second was also settled by a single break, before the third went to tie-break, with Bolelli making two mini-breaks to seal a memorable win.

"There were many close games, but I couldn't make the most of my chances," said Raonic. "I served better as the match went on, but he made it through when it mattered the most."

Bolelli faces Gael Monfils in the last eight.

Raonic's exit left Stan Wawrinka as the top remaining seed and the Swiss wasted little time in seeing off Benoit Paire 6-2 6-3.

Wawrinka broke serve twice in a comfortable first set and, after surviving four break points at the beginning of the second, faced little resistance on his way into quarter-finals.

Meanwhile, Davd Goffin retired during the first set of his clash with Dominic Thiem.