After falling a set behind against Christina McHale in the second round, Serena Williams was unwilling to accept another early exit in Auckland.
Serena Williams looked like she was going to suffer another second-round exit at the ASB Classic.
The top seed, seeking her first WTA Tour title in three years, trailed fellow American Christina McHale after dropping her serve three times in losing the first set.
But Serena, seeking a record-equalling 24th Grand Slam at the Australian Open later this month, had some harsh words for herself.
And that did the trick as the 38-year-old powered back to claim a 3-6 6-2 6-3 victory in exactly two hours.
“I got myself in a hole and I was able to get out of it, so that was satisfying,” said Serena Williams.
“I just got mad, and honestly, I said that I wanted to win more than one match here in New Zealand.
“I thought about that, and sometimes, it’s the craziest things that get you motivated.
“I just was making a lot of errors and I stopped making so many. I tried to be a little more aggressive. I was playing a player who was playing unbelievable, so I had to play better.”
Many analysts have suggested Serena’s Grand Slam final defeats over the past four years have come due to a lack of regular matches in other WTA Tour competitions.
And, discussing the match in her on-court interview, she did feel this was exactly the type of challenge she needed while preparing for a major.
“It was a good match for me, because I really need to play matches like that to get to my goals,” added Serena Williams.
“Tournament time is super important and match time is good. It’s fun to be out here after losing that first set, and I’m glad I’m still in the event.
“I just thought I needed to figure out a way to win this match.”
Serena spoke before the tournament about her unhappy last trip to Auckland which came while she was unaware she was pregnant and also saw her endure a second-round defeat.
She has gone further this time and now meets Siegemund, a player she emphatically beat in Indian Wells back in 2016, their only career meeting.
Serena Williams also has a doubles semifinal to play in a busy end to the week, a competition in which she and Wozniacki could face Gauff and her partner Caty McNally in the final.
Wozniacki joins Serena in last eight
Serena’s doubles teammate and close friend Wozniacki also had to work extremely hard to progress in the singles.
Playing the penultimate event of her career, Wozniacki was a break down in the deciding set but battled to victory over Lauren Davis.
The Dane won 6-1 4-6 6-4 and faces a big test in the quarterfinal against Julia Goerges, the defending champion at this tournament who defeated Jil Teichmann in straight sets.
The resurgent Eugenie Bouchard’s match against American prospect Amanda Anisimova is one of the other quarterfinals.
Jessica Pegula and Alize Cornet are the other two players still in the singles tournament.