SERENA Williams admits Heather Watson had her contemplating a shock Wimbledon exit before the American came through a three-set thriller on Centre Court.
Watson was up two breaks and led 3-0 in the third set, and the British number one later served for the match at 5-4, but Williams roared back to win 6-2 4-6 7-5.
Williams will now play her sister Venus in the last 16 as she looks to clinch her sixth Wimbledon title and 21st grand slam overall.
“I honestly didn’t think I was going to win,” Williams said. “How I pulled through, I really don’t know.
“I just was like, ‘listen, if I’m going to go lose, I’m going to lose trying to do the right things.”’
Williams continued: “I’m actually more negative than one would think.
“I’m like, ‘I guess I’m going to do this tomorrow’. I’m not really thinking about the match.
“Next thing, I’m playing a point, maybe it takes my mind off things.
“It’s not that I thought I was going to lose. I just felt like she was playing really well. I wasn’t able to keep up.
“Sometimes you just don’t have your day. I thought maybe today just wasn’t my day.”
It means the Williams sisters will meet for a sixth time at Wimbledon, with four of their previous match-ups coming in the final at SW19, and Serena emerging victorious on three occasions.
In 25 matches against each other, Serena has won 14 times and Venus 11.
Venus may have the benefit of fresher legs, however, after the seven-time major champion eased to a 6-3 6-2 win over Serbian Aleksandra Krunic.
Maria Sharapova will have an eye on the Williams contest as she remains on track to meet the winner in the semi-finals after the number four seed beat Romanian Irina-Camelia Begu 6-4 6-3.
Sharapova was crowned champion at the All England Club in 2004 but in the 11 years since, she has only gone past the fourth round three times.
“When I won the tournament is certainly something that I think about every time I step into the grounds,” said Sharapova, who will now play Kazakhstan’s Zarina Diyas.
“The memories of being a champion and the experience of going through those two weeks not expecting myself to be the champion at that stage in my career, yet holding up the plate, I always carry those memories with me every time I step on the court here.”
Sharapova’s French Open conqueror Lucie Safarova is also through after she came from a set down to beat American Sloane Stephens, while Victoria Azarenka progressed in straight sets against Kristina Mladenovic.
