Paris - Serena Williams battled back from a set down for the second straight match to defeat Victoria Azarenka 3-6, 6-4, 6-2 and reach the last 16 of the French Open on Saturday.
The 33-year-old American was staring defeat in the face at a set and 2-4 down in the second before finding her range in the nick of time.
She was also a break down early in the deciding set, but by that time she had found her range and she duly won six games in a row to clinch the win.
Williams will next play fellow American Sloane Stephens for a place in the quarter-finals as she continues in search of a 20th Grand Slam title.
"Today it was not easy, Victoria played very well and I was struggling," said the two-time champion.
"She won the first set and I just said to myself 'allez, allez Serena, come-on.'"
Azarenka was quickest out of the blocks in a late-starting match, taking the opening two games before Williams levelled at 2-2. Azarenka then won four of the next five games to take the set 6-3.
Williams was struggling with her usually mighty serve and she was broken again in the third game of the second set as Azarenka grew in confidence to take a 3-1 lead.
The American had a break point to get back level at 3-3 but three unforced errors in a row saw her 4-2 down instead.
Two games later she had another shot at taking the Azarenka serve and this time she made no mistake on her second break point with the Belarusian hitting long under pressure.
That proved to be the turning point of the match with Williams clearly in the ascendancy suddenly opening up with all the power she has at her disposal.
She levelled the set scores after a disputed line call that had the two players trading barbs and staring daggers at each other over the net.
Williams fell behind 0-2 at the start of the deciding set, but turned on the power as Azarenka wilted to win the last six games of the tie. Results from the sixth day of the French Open at Roland Garros on Saturday (x denotes seeded player):
Novak Djokovic (SRB x1) bt Thanasi Kokkinakis (AUS) 6-4, 6-4, 6-4
Richard Gasquet (FRA x20) bt Kevin Anderson (RSA) 4-6, 7-6 (7/4), 7-5, 6-4
Jack Sock (USA) bt Borna Coric (CRO) 6-2, 6-1, 6-4
Rafael Nadal (ESP x6) bt Andrey Kuznetsov (RUS) 6-1, 6-3, 6-2
Andy Murray (GBR x3) bt Nick Kyrgios (AUS x29) 6-4, 6-2, 6-3
Jeremy Chardy (FRA) bt David Goffin (BEL x17) 6-3, 6-4, 6-2
Marin Cilic (CRO x9) bt Leonardo Mayer (ARG x23) 6-3, 6-2, 6-4
David Ferrer (ESP x7) bt Simone Bolelli (ITA) 6-3, 1-6, 5-7, 6-0, 6-1
Serena Williams (USA x1) bt Victoria Azarenka (BLR x27) 3-6, 6-4, 6-2
Sloane Stephens (USA) bt Tsvetana Pironkova (BUL) 6-4, 6-1
Sara Errani (ITA x17) bt Andrea Petkovic (GER x10) 6-3, 6-3
Julia Goerges (GER) bt Irina Falconi (USA) 6-4, 6-1
Petra Kvitova (CZE x4) bt Irina Begu (ROM x30) 6-3, 6-2
Timea Bacsinszky (SUI x23) bt Madison Keys (USA x16) 6-4, 6-2
Andreea Mitu (ROM) bt Francesca Schiavone (ITA) 7-5, 6-4
Alison Van Uytvanck (BEL) bt Kristina Mladenovic (FRA) 6-4, 6-1