Juan Monaco is through to the quarter-finals of the Paris Masters after American number one Mardy Fish pulled out in the third-round tie after suffering what appears to be a groin injury.
The 29-year-old was poised to clinch the victory until his opponent forced him to a tie-break and third set.
The two competitors were fairly matched in the initial stages of the first set, until Fish made his presence known and claimed two breaks to grab the advantage.
The American went on to dominate and take the lead with six games to one, leaving the Argentinian with no choice but to relinquish the first set.
The 27-year-old tried to hold on in the second set, with each game going by the way of serve.
While Monaco built up a level of pressure on the world number nine, Fish failed to regain the advantage and was forced to take the set to a tie break.
The Argetinian's refusal to give up paid off as he took the second set eight points to six in the tie break.
Mid-way through the final set Fish felt strained and was forced to withdraw from the court, which gifted Monaco the quarter-final spot.
