World No. 1 Aryna Sabalenka completed a hard-fought comeback against Laura Siegemund to avoid elimination and move on to the semifinals at Wimbledon.

She still has a long way to go before the final, but whatever happens from here, this was a crucial victory for the world No. 1.

Martina Navratilova, the ultimate grass-court champion, explains why Aryna Sabalenka's versatile game makes her the player to beat at Wimbledon.