David Ferrer beats Stanislas Wawrinka in World Tennis Championship
Trailing 5-3 in the first set, Ferrer won the next nine games to effect a fantastic turnaround. The Spaniard will now face compatriot Rafael Nadal in the semi-final today.
The 31-year-old had lost to Nadal in the final of the French Open last season.
In the other match of the day, Frenchman Jo-Wilfried Tsonga defeated Andy Murray 7-5, 6-3.
Ferrer recently split with his coach Javier Piles after a 15-year working relationship.
“I am sad because it was a very familial relationship and next year I will begin with Jose Altur along with my same team,” he said.
Ferrer and Piles had endured a close but sometimes roller-coaster relationship. The coach once locked Ferrer in a cupboard as punishment for a poor performance on the practice courts.
Ferrer is the second Top 3 player to change coaches in the last week after World No 2 Novak Djokovic hired Boris Becker as his head coach.