World number six Tomas Berdych was given a going over by Nikolay Davydenko at the Barcelona Open before eventually seeing him off 3-6 7-5 6-4 to secure a spot in the last 16.
Berdych is seeded three at the Real Club de Tenis and so had a bye into the second round, but looked out-of-sorts against his Russian opponent.
He saw his serve broken twice in the first set, allowing Davydenko to move into the lead.
The 27-year-old dug deep to turn things around in the second set, though he still only managed to edge it 7-5.
Berdych was the better player in the third set, sealing victory with his ninth ace of the game. He will now go on and play the winner of the game between Grigor Dimitrov, the 14th seed, and Spain’s Tommy Robredo for a place in the quarterfinals.
Elsewhere Latvian qualifier Ernests Gulbis provided the shock of the day, knocking out 12th seed Fernando Verdasco 6-3 6-4.
‘King of clay’ Rafael Nadal begins his quest for an eight title in nine years with a match against Carlos Berlocq.
Nadal, favourite in the Barcelona Open betting
, saw his 46-uneaten run at the Monte Carlo Masters brought to an end by Novak Djokovic last Sunday, raising suggestions that his injury woes have weakened his dominance on clay.
He is seeded second behind fellow Spaniard David Ferrer, who lost to Nadal in the finals of 2008, 2009, 2011 and 2012.
Ferrer will play Russian qualifier Dmitry Tursunov in his second round clash on Wednesday.Click here if you want to Bet on Betfair Tennis
markets throughout the tournament.