April 24 Russian qualifier Dmitry Tursunov stunned top seed and world number four David Ferrer 7-5 3-6 6-1 in the second round of the Barcelona Open on Wednesday.
Four-time finalist Ferrer had pulled out of the Monte Carlo Masters event last week with an unspecified leg injury picked up when losing in the Miami final to Andy Murray last month.
The Spaniard capped an error-strewn display in sunny, but blustery conditions when he overhit a cross-shot to hand Tursunov victory.
Rafa Nadal, who beat Ferrer in last year's final, starts his bid for an eighth Barcelona title against Argentine Carlos Berlocq later on Wednesday.
(Reporting by Mark Elkington, editing by Justin Palmer)