Italian ace Sara Errani beat Agnieszka Radwanska 6-4 7-6 at Roland Garros to make the semi-finals of the French Open.
Last year's finalist had served for the match at 5-4 but Radwanska won to love before the set went to a tie-break, which Errani took 8-6.
Her match against Radwanska was a contrast to the other quarter-final happening across Roland Garros, with guile and touch the order of the day rather than power.
It was tight all the way through but Errani was always the player forging ahead and she eventually saw out the win.
She will now play No 1 seed Serena Williams in the last four, the American surviving a scare from former champion Svetlana Kuznetsova to progress.
Williams took the first set easily 6-1 but the 2009 champion, who was unseeded in this tournament, dug deep to take the next 6-3.
Williams dropped serve for the first time in the tournament in the set, being broken three times, and she was again in trouble against her Russian opponent in the decider, trailing 0-2.
But she fought off two break points that would have seen her slip to 0-3 and won six of the last seven games to secure victory in a shade under two hours.
The victory saw Williams extend her winning streak to 29 matches as she aims to claim her first French Open title since 2002.