Defending champion Andy Murray and ATP finals hopefuls Mikhail Youzhny and Fernando Verdasco all made surprise early exits from the Valencia Open on Wednesday.
World number four and top seed Murray fell 6-2, 3-6, 6-2 to Argentine Juan Monaco in the second round, while world number 10 Youzhny pulled out at the start of the day with a back problem.
The Russian was due to play Uruguayan qualifier Pablo Cuevas in his opening match, but had to give his place over to Spaniard Albert Ramos-Vinolas who lost 6-3, 6-4.
Spaniard Verdasco, the third seed and world number seven, was crushed 6-1, 6-3 by Frenchman Gilles Simon.
Youzhny and Verdasco's exits damaged their chances of making the season-ending ATP finals later this month, as they fought for the three remaining berths in London.
Rafael Nadal, Roger Federer, Novak Djokovic, Murray and Robin Soderling have qualified so far, the latter is also competing in Valencia.
David Ferrer and Nikolay Davydenko have the chance to push their claims for London in the quarter-finals on Thursday, when second seed Soderling also plays.
