Gilles Simon's bid for a fourth title in Bucharest came crashing down after he was beaten in the quarter-final by Spain's Daniel Gimeno-Traver.
Simon had defeated Janko Tipsarevic on Thursday and looked odds-on to clinch yet another victory en route to the final of the BRD Nastase Tiriac Trophy.
Indeed, Simon won the first set on a tie break but the top seed somehow managed to lose his bearings as Gimeno-Traver battled back to claim a 6-7 (5/7) 6-4 6-2 triumph.
The pair's only previous meeting had come at the 2009 US Open where it was Simon who emerged victorious in three sets at Flushing Meadows.
Gimeno-Traver had seen off qualifier Nikola Mektic in the previous round on Thursday, and fought back brilliantly from the set down on Friday, taking the one crucial break that levelled the match up at 1-1.
Three further breaks for Gimeno-Traver wrapped up the deciding set, and continues the Spaniard's rise after he broke back into the top-100 rankings in February.
He set up a clash against Jiri Vesely, who kept up his encouraging start to the 2015 season by making a third tour-level semi-final berth.
Vesely got past third seed Ivo Karlovic 6-4 6-4 and was quoted on the ATP website as saying: "It is my third semi-final this year, which is very nice.
"I have confidence and I'm looking forward to advancing to the final if possible. I was prepared to play two or three tie-breaks, if necessary, but I'm happy that I was able to convert when break opportunities occurred."
Lukas Rosol, a winner here in 2013, was also knocked out of the last eight with Guillermo Garcia-Lopez getting through 6-4 7-6(9/7) in straight sets to set up a clash with second seed Gael Monfils.
Monfils eased past eighth seed Simone Bolelli 6-3 7-6 (7/4).
Source: PA
