The WTA 1000 on Madrid’s clay is fully into its role now, sorting the contenders from the pretenders as the draw tightens. Day 6 brings third round action to a close and as always, we here at LWOT will be offering our predictions for every match on the schedule. But who will advance?
WTA Madrid Open Day 6 Predictions
Jessica Pegula vs Marta Kostyuk
Head-to-Head: Pegula 4–2 Kostyuk
These two have met six times, with Pegula holding a 4–2 edge overall, though Kostyuk turned the tables emphatically at Brisbane in January, winning 6–0 6–3 in the semifinals. All their meetings have come on hard courts, so this is genuinely new territory for both. On clay, Pegula has been quietly excellent, winning the title in Charleston a few weeks ago. Kostyuk is a dangerous, aggressive ball-striker who can dismantle opponents on her best days, but her clay results don’t match her hard-court form. Pegula comes in at 6–0 on clay in 2026, and on this surface, she should be able to absorb Kostyuk’s pace and dictate on her own terms. The American’s consistency and clay-court pedigree give her the edge here.
Prediction: Pegula in 3
Caty McNally vs Katerina Siniakova
Head-to-Head: Siniakova 1–0 McNally
McNally recorded the first Top 10 victory of her career at this tournament, beating Victoria Mboko 6–4 6–1, and she is clearly hitting her stride after a difficult spell following wrist surgery. The 24-year-old American serves big and moves well, and she has been pressing opponents with her aggressive returning all week. Siniakova, though, is a seasoned clay-court operator. The Czech holds a 1–0 head-to-head advantage, and she comes in at 2–0 on clay in 2026. Their only prior meeting went Siniakova’s way, and her experience in these kinds of tight third-round matches at WTA 1000 events should count for something. McNally will push her, but Siniakova’s clay-court nous is likely to see her through.
Prediction: Siniakova in 3
Zeynep Sonmez vs Solana Sierra
Head-to-Head: First meeting
This is the first time these two have met on the main tour. Sonmez has been in fine fettle on clay in 2026, posting a 5–1 record on the surface, while Sierra arrives at 2–1 on clay this season. Sierra had a solid run to reach this stage, beating Magdalena Frech in straight sets in the previous round, but she has not played at this tournament before. Sonmez, by contrast, is comfortable on red clay and has shown real competitive grit here, saving a set against Bucsa before coming through in three. Sonmez’s break-point conversion rate has been excellent in Madrid, breaking her opponents 14 times at a 54% conversion rate. That clinical edge should be enough to see her past a dangerous but less experienced opponent.
Prediction: Sonmez in 2
Elena Rybakina vs Qinwen Zheng
Head-to-Head: Rybakina 3–1 Zheng
This will be their first meeting on clay, which adds genuine intrigue to what is already a fascinating matchup. Zheng is only five wins into her 2026 season after months on the sidelines rehabbing an elbow injury , and she admitted her first set against Kenin was a rocky one. The good news for her is that she found a way through, adjusting her game and showing the fighting spirit that took her to Olympic Gold. Rybakina, meanwhile, comes in with a 4–0 clay record in 2026 and claimed the Stuttgart title just weeks ago. She did struggle against Ruse in round two, racking up 58 unforced errors, but found a way to win in three sets. Rybakina’s serve is the great equalizer on clay, and she has far more competitive clay-court time under her belt this season than Zheng, who is still getting her bearings back on the surface. That gulf in preparation should prove decisive.
Prediction: Rybakina in 3
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