Fernando Verdasco suffered a surprise second-round loss at the Ecuador Open as his Spanish countryman Feliciano Lopez battled through.
Verdasco, the fourth seed, was downed by Argentine qualifier Renzo Olivo 7-6 (7-5) 3-6 6-3 on the clay courts in Quito on Thursday.
The left-hander was up a break at 3-1 in the third set before losing five consecutive games.
Since his stunning win over Rafael Nadal in the Australian Open first round, Verdasco has lost back-to-back matches.
Olivo advances to a quarter-final meeting with Victor Estrella Burgos after the defending champion beat qualifier Andrej Martin 7-5 6-1.
Estrella Burgos overcame Lopez in last year's final and the latter is also still alive.
The Spanish second seed battled past Brazilian qualifier Joao Souza 4-6 7-6 (7-5) 6-2.
Lopez served 14 aces in his win, with his only breaks of serve coming in the deciding set.
He will meet countryman Albert Ramos-Vinolas in the last eight after the seventh seed overcame Rajeev Ram 6-7 (5-7) 6-3 7-5.