Ashleigh Barty defeated Iga Swiatek 7-5 6-4 in the last 16 of the Mutua Madrid Open.
The win was the 14th consecutive victory on red clay, and she was pushed all the way by her younger Polish rival.
She was in for a scare when she went down 3-0 in the opening set, but thereafter did not drop a service game.
Superb Sorribes Tormo dumps Barty out of Olympics
- Evans battles past Chardy in tricky opener in Madrid
- Jamie Murray falls in Madrid, Norrie loses Estoril final
- Up to 1,000 fans per court at French Open - minister
Ultimately, Australian world number one Barty showed more resilience as she saved six out of the seven break points offered up to Swiatek, while she took all three of those she earned.
Serving up six aces to her opponent’s two also helped her push through her advantage on serve, and she is now through to the quarter-finals in Spain, where she will play the Czech Republic’s Petra Kvitova.
Trailblazers - Serena Williams: A champion on and off the court who faced down prejudice
Osaka, Barty, Watson begin bid for Olympic tennis glory this weekend
Murray gets tough Olympic draw - faces Auger-Aliassime in singles opener