US Open Women's Singles Quarter-Final Tips: Vondrousova an underdog option against Keys

• Gauff and Muchova ease to wins

• Sabalenka likely to see of threat of Zheng

• Keys could be blunted by Vondrousova's return

Gauff now into market leader following Tuesday triumph

Both Cori Gauff and Karolina Muchova eased into the semi-finals with routine wins over Jelena Ostapenko and Sorana Cirstea, respectively, and both also won their first set via a bagel scoreline.

That in itself shows the impressive nature of their performances and Gauff is now the favourite tournament winner market at a current 2.9215/8. Aryna Sabalenka 3.2011/5 will shorten markedly if she wins tonight, while Muchova 6.611/2 is the clear third favourite.

Sabalenka a strong favourite over Zheng

Sabalenka will need to get past the threat of Qinwen Zheng if this is to happen, and is 1.3030/100 to do so at the current Exchange market prices.

The duo have never met in professional tennis, and hard court data this year gives Sabalenka a clear edge, holding serve around 7% more and breaking oppositions over 5% more as well.

Given the higher calibre of opposition Sabalenka has faced this season (more than double the number of top 10 opponents than Zheng), it's really difficult to make a data-driven argument that the market prices are incorrect here.

Sabalenka has bossed four players so far to get to this stage, winning every set by a 6-1 to 6-3 scoreline, and while Zheng should be no pushover, it would be a fairly big surprise if Sabalenka was ousted today.

Vondrousova can pick up the Keys to victory

The other semi-final looks more competitive, with Madison Keys having a slight market edge at 1.834/5 over Marketa Vondrousova. This is despite Wimbledon champion Vondrousova winning a much greater percentage of return points on hard court this year, with a smaller deficit on serve.

Apart from one tiebreak set against Peyton Stearns in the last round, Vondrousova hasn't been troubled to get here, winning every set by 6-3 or better, and while Keys has impressed too, particularly in the last round against Jessica Pegula, I can't help thinking that the market has overvalued her following that victory.

With this in mind, I'm quite keen on Vondrousova at underdog prices. I think Keys looks like a false favourite here, and it's also worth noting that when she's been a slight favourite against left-handers in her career, Keys has struggled. Let's see if that continues today.