Williams, 36, now heads to the semi-finals to compete against German tennis player, Julia Gorges.
"I hate losing. That's no secret", the 23-times major victor said after digging deep to deny Camila Giorgi a famous victory with a rousing 3-6 6-3 6-4 quarter-final comeback win over the unseeded Italian. I had multiple surgeries and almost didn't make it when I gave birth.
"You're only as good as your last win".
In a matchup of the only two mothers remaining in the draw, Williams jumped into a 3-0 lead in both sets and wrapped up the win in 62 minutes.
"It's important for me to have the losses".
Williams dropped her first set at this tournament as the 52nd-ranked Giorgi produced an impressive display of power and accuracy in the opener.More news: Apple Releases tvOS 11.4.1 for Apple TV [Download]
"Everything right now is a little bit of a surprise", the American said. I mean, I always say I plan on it, I would like to be there, have these goals. "But when it actually happens, it still is, like, Wow, this is really happening".
With Olympia's arrival and her marriage to husband Alexis both taking place since Serena was last at Wimbledon, this year's campaign has a unique feel.
"It's different now obviously because I have the baby. Being a mom is totally different", she said. "'I'll just keep fighting", Williams said.
Andy Murray has backed Wimbledon's decision to relegate Roger Federer to Court 1 for his quarter-final match against Kevin Anderson.
But the 29-year-old has erased those painful memories with a superb run, capped by a come from behind success against Bertens in her first Grand Slam quarter-final.
Nine-time Wimbledon champion and BBC pundit Martina Navratilova said: "She's been healthy here, hitting the ball hard and the seas have parted for her".More news: Shocking video of glacier fracturing shows true extent of climate change
'Wow, it's pretty incredible, ' Goerges said afterwards.
Serena Williams celebrates after winning against Italy's Camila Giorgi during their women's singles quarter-final match on the eighth day of the 2018 Wimbledon Championships at The All England Lawn Tennis Club in Wimbledon, London, July 10, 2018.
Goerges, who had never made it past the third round in her 10 previous appearances at the All England Club, advanced with a comeback victory over Bertens. Probably because at the French Open a couple weeks ago I had so much pressure.
"It was a very tough match but I was just trying to enjoy it. It's so much fun".
Del Potro was thrashed by the Spaniard in the French Open semi-finals last month but feels his game matches up better against the No.1 on grass despite losing their only two meetings on the surface.
In March, she lost in the first round of the Miami Open to Naomi Osaka, leading to a hasty exit in which she bypassed a postmatch media session.More news: France out to rectify Euro 2016 mistakes in final, says Pogba
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