Marta Kostyuk's perfect clay season faces its biggest test yet as she meets Mirra Andreeva in the Ladies Roland Garros 2026 semifinal.

Marta Kostyuk has not lost on clay in 2026. Seventeen matches, seventeen wins, and a maiden WTA 1000 title in Madrid to show for it.

Now the Ukrainian stands one match from a first Grand Slam final, with only Mirra Andreeva between her and Saturday's showpiece.

The pair met in that Madrid final just five weeks ago, and Kostyuk won in straight sets. Andreeva will want revenge, but history is stacked against her.

• Competition: Roland Garros 2026, WTA Semifinal
• Venue: Court Philippe-Chatrier, Paris, France
• Date: Thursday, June 4, 2026
• Start Time: 11:00 PM AEST (Thursday) - Not before 3pm local time

Kostyuk vs Andreeva Form and Head to Head

Kostyuk leads the head-to-head 3-0, with both wins coming in recent meetings.

On clay specifically, she beat Andreeva 6-3, 7-5 in the Madrid final, with Andreeva holding a set point in the second set before Kostyuk broke back at 5-6 to take it.

Their other meeting came at Brisbane on hard court earlier this year, where Kostyuk also prevailed.

Kostyuk's run to this point has been remarkable. She dispatched four-time champion Iga Swiatek 7-5, 6-1 in the fourth round, then accounted for seventh seed Svitolina in the quarters.

Her 17-0 clay record this season is one of the longest winning streaks on clay in recent WTA history.

Andreeva brings serious form of her own, with 33 match wins in 2026, among the most of any woman on tour.

Her quarterfinal demolition of Cirstea (6-0, 6-3) was a statement, and at 19 she's already making her second Roland Garros semifinal after reaching the last four as a 17-year-old in 2024.

Kostyuk's Clay Season Rewrites the Record Books

Kostyuk's 17-0 clay run puts her in elite company this century, joining Venus Williams, Justine Henin, Serena Williams and Swiatek among those who have dominated the surface early in a season.

No injuries have been reported for either player heading into the semifinal, though Kostyuk has carried significant emotional weight throughout the tournament after speaking publicly about a missile attack on Kyiv following her first-round win.

If anything, the adversity has sharpened her focus.

Andreeva will draw confidence from the Madrid final second set, where she came close before Kostyuk broke back to seal it 7-5. The 19-year-old knows she was right there.

Russian tennis great Yevgeny Kafelnikov, who has been publicly critical of Andreeva's performances throughout 2026, adds an extra layer of intrigue to a semifinal that hardly needed it.

Kostyuk vs Andreeva Betting Markets

With a first Grand Slam final on the line for both players, the match winner market is the headline act.

Check out the full range of Kostyuk vs Andreeva odds and markets available at Sportsbet before the first ball is struck.

The first set winner market is worth a close look given Kostyuk's pattern of fast starts on clay.

Total sets and total games markets could also provide value, particularly if you expect Andreeva to push this one deeper than the Madrid final but ultimately fall short.

Player games handicaps offer another way in for punters who rate Kostyuk but expect a competitive contest.

Kostyuk vs Andreeva Prediction: Our Pick

Kostyuk looks set to continue her historic clay run and book a place in the Roland Garros final.

The numbers are hard to argue with. Kostyuk is 17-0 on clay this season, 2-0 in the head-to-head, and has beaten Andreeva on this surface in the Madrid final already in 2026.

She's knocked off the tournament's four-time champion in Swiatek and hasn't looked troubled doing it.

Kostyuk has also been sharp out of the blocks throughout the clay swing, which makes her a strong play in the first set winner market as well.

The risk is that Grand Slam semifinals bring unique pressure, and neither player has been to a major final before.

Andreeva's youth and fearlessness could make for uncomfortable moments, particularly if she can push deep into a second set as she nearly did in Madrid.

But Kostyuk's composure under pressure this fortnight, combined with the psychological edge of recent dominance over this opponent, should prove decisive.