WTA semi-final tips: Zheng backs up unbeaten run against Mertens

Saturday night's WTA semi-final brings together two players in blistering touch, both coming off statement wins and carrying perfect five-match winning streaks into the knockout. Qinwen Zheng, the world number 54, meets Belgium's Elise Mertens, ranked 19th, with first serve at 10:00 pm AEDT on Saturday, 10 October.

Zheng scraped past Elina Svitolina in a tight three-setter on Friday night, while Mertens dismantled Iga Swiatek in straight sets the same evening — a result that underlined her current threat level. The only prior meeting, back in April 2025 on clay, went Zheng's way in comfortable straight sets, but that was a different surface and a different stage of the season. Both players have reinvented themselves since then, and the match-winner market reflects a genuine contest: Zheng sits at $1.65, Mertens at $2.25.

Who takes it?

Zheng's form line reads like a knockout tournament script: four consecutive wins without dropping a set until Friday's Svitolina test, which she eventually navigated 6–7, 6–3, 6. She's won 20 of 33 this season for a 61 per cent strike rate, and the Chinese right-hander has been clinical when it matters — every one of her last five victories has come in straight sets or tight three-set battles where she held her nerve late.

Mertens, meanwhile, carries a 34–19 year-to-date ledger (64 per cent) and the ranking pedigree to match. Her last five reads W–W–W–W–L, with that solitary loss coming back in early August against Naomi Osaka. Since then, she's reeled off four on the trot, including wins over Jelena Ostapenko and Katie Volynets on the road before Friday's clinic against Swiatek. The Belgian's career record (334–213, 61 per cent) speaks to longevity and consistency, and she's twice reached as high as world number 12.

The head-to-head offers Zheng a sliver of psychological edge: she won their only prior meeting 6–3, 6–3, 6–3 on clay in April 2025, never facing a break point across the match. But Mertens has levelled up since that spring afternoon, and her current winning streak suggests she's peaking at the right moment. When it comes to tennis predictions, backing the player who just dismantled a top opponent in straight sets is never foolish — yet Zheng's unbeaten home run and that h2h victory keep her narrowly ahead in the punters' eyes.

Set handicap yarn

The sets line has Zheng laying 1.5 sets at $2.60, with Mertens getting the 1.5-set start at $1.45. In other words, you're backing Zheng to win in straight sets or taking Mertens to claim at least one. Zheng's recent set-winning consistency argues for the favourite: three of her last four wins came in straights before Friday's three-setter, and even that Svitolina match saw her recover emphatically after dropping the first set on a tiebreak.

Mertens, though, has shown she can go the distance when required — her win over Ostapenko went three sets, and the Swiatek demolition was a statement in efficiency rather than dominance (7–6, 6–3 still means both sets were competitive until the crucial moments). The set handicap market is pricing in Mertens' quality: she's good enough to steal a set even if she doesn't win the match, and that 1.5-set buffer at $1.45 reflects punters expecting a contest rather than a procession.

Games total ledger

The total games line sits at 22.5, with over priced at $1.95 and under at $1.85. That's a tight market, reflecting uncertainty about how the match unfolds. If both players hold serve for stretches and trade tiebreaks, the over is live; if one asserts early and runs away with it, the under comes into play.

Zheng's recent matches have delivered variety: her Svitolina clash would have sailed over (three sets with a tiebreak in the first equals plenty of games), while her earlier straight-set wins were brisk affairs. Mertens' Swiatek win clocked 7–6, 6–3 — that's 22 games, just under the line. The April 2025 head-to-head between these two finished 6–3, 6–3, 6–3 (18 games), comfortably under, but both have lifted their level since then and neither is handing out cheap service breaks. The under sits favourite for a reason, but the market's tightness suggests punters are split.