​Elina Svitolina won the season-ending WTA Finals in 2019 [Reuters]Elina Svitolina says she “got a bit angry at myself” to inspire a comeback victory over Karolina Muchova at the WTA Finals and keep her semi-final hopes alive.Ukraine’s Svitolina lost 6-4 6-0 in her first group match against Mirra Andreeva on Monday and made an equally poor start against Muchova.It looked as though things were getting worse for Svitolina when she took a medical timeout for a right hip injury after losing the first set, before finding herself an early break point down.However, the sixth seed saved it and then gradually wore down Wimbledon runner-up Muchova to win 3-6 6-2 6-2.Muchova hit 39 unforced errors throughout the match – the majority of which came from her forehand – as Svitolina ground her down.The Czech could not recover from giving up an early break in the third set and handed over another with her eighth double fault of the match.Svitolina made no mistake, with the 32-year-old tipping her head back and roaring in celebration after securing the win.”I was really angry at myself after the first match and the first set,” Svitolina told Sky Sports.”Sometimes it [channelling frustration] happens in a good way and sometimes in a bad way.”I tried to direct my anger towards the ball and I found my game in the end.”It is Svitolina’s ninth victory over a top-10 player this year, and her first at the WTA Finals since she won the title in 2019.Svitolina can still qualify for the last four in California – but she will not know what she needs to do until after Aryna Sabalenka’s match against Andreeva.At the Stockholm Open, Britain’s Cameron Norrie fell 7-5 6-3 to world number 10 Taylor Fritz.Denmark’s Holger Rune reached the quarter-finals of the tournament, a year after he ruptured his Achilles at the same event.Rune only made his return to the ATP Tour in October after a gruelling 12 months recovering from the injury, but beat Miomir Kecmanovic 2-6 6-1 6-4 to advance.Raducanu to return at January’s United Cup after injury lay-offBrilliant Noskova dismantles Gauff to reach WTA Finals last four