Top two seeds Bernard Tomic and Feliciano Lopez crashed out at the quarter-final stage of the Ecuador Open in Quito.
Top seed Tomic was beaten in three sets by Italian Paolo Lorenzi, who triumphed 6-7 7-5 6-3 on the clay in South America.
Second-seed Lopez was on the way to a straight-sets defeat to fellow Spaniard Albert Ramos-Vinolas when he retired after feeling unwell. Ramos-Vinolas was leading 7-5 4-3 when Lopez called it a day.
Lopez said: "After a long game I felt my heart-rate go up and it didn't return to normal. I had no energy and was not 100 per cent."
His retirement hands Ramos-Vinolas a semi-final tie against Victor Estrella Burgos after he fifth seed needed three sets to see off Argentinian Renzo Olivio 6-4 6-7 6-4.
Third-seed Thomaz Belluci will face Lorenzi in the other semi-final as he battled past Pablo Carreno Busta 7-6 4-6 6-2.
Source: PA