Five-time champion Venus Williams won in her 100th singles match at Wimbledon to knock out French Open winner Jelena Ostapenko and reach the semi-finals.
Williams earned a 6-3 7-5 victory against the 20-year-old Latvian in one hour and 13 minutes on Centre Court.
She will play Britain's sixth seed Johanna Konta in the last four on Thursday after Konta knocked out second seed Simona Halep.
Garbine Muguruza will play Magdalena Rybarikova in the other semi-final.
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American Williams, 37, is the oldest player to reach the last four since Martina Navratilova in 1994, but says she doesn't think about her age.
"I feel quite capable, to be honest, and powerful," she said.
"So whatever age that is, as long as I feel like that, then I know that I can contend for titles every time."
Williams, competing at her 20th Wimbledon, is just one victory away from her ninth final at SW19 - eight years after her last appearance.
She has not won a Grand Slam title since Wimbledon in 2008.
Veteran Venus outpowers youngster
Williams dominated Wimbledon for almost a decade between 2000 and 2009, winning five titles and finishing runner-up in another three finals.
But the seven-time Grand Slam champion had become a peripheral figure after being diagnosed with Sjogren's syndrome, an illness that causes fatigue and joint pain, in 2011.
She says she refused to consider retirement, despite her world ranking plummeting to 103 by the end of 2011.
The American returned to the top 10 last year and then reached her first Grand Slam final since 2009 when she lost to sister Serena at the Australian Open final in January.
Now she is just one more victory away from another major final after beating an opponent who was only born a couple of weeks before she made her SW19 debut in 1997.
Ostapenko confirmed her status as one of the rising stars of the women's game when she earned a surprise victory at Roland Garros last month.
But her aggressive, risk and reward game came unstuck against the powerful Williams serve.
A single break point taken in Ostapenko's first service game was enough to swing the opening set in Williams' favour, before the hard-hitting Latvian finally began to match her opponent's power in the second.
Ostapenko wiped out a break for 3-3, only to see Williams ramp up the pressure to break for 6-5, holding out to love for her 86th singles victory at Wimbledon.
"She was serving really well. It was very tough to break. Because of that I had more pressure because I had to keep my serve," said Ostapenko.
"I was not feeling nervous. I just couldn't really play my best."
Winning feeling helps at Wimbledon - analysis
Martina Navratilova, nine-time Wimbledon singles champion
Venus is the only one who's done it before and that really pays off.
Ostapenko has done well to get into the last week.
Until you win it the first time you don't know if you can and that doubt can add to you on court.
Muguruza to face remarkable Rybarikova
Spaniard Muguruza, who reached the final at SW19 in 2015, beat Svetlana Kuznetsova 6-3 6-4 in one hour and 15 minutes on Court One.
The 14th seed is coached by Conchita Martinez, the only Spanish player to have claimed the women's singles title at Wimbledon when she won in 1994.
Muguruza will now play Rybarikova on Thursday after the Slovak overpowered a wayward Coco Vandeweghe in a match which was switched to Centre Court after rain halted play at 2-2 in the second set.
Unseeded Rybarikova was ranked outside of the top 400 in the world as recently as March after knee and wrist injuries and was appearing in her first Grand Slam quarter-final.
She is the eighth‐lowest‐ranked Grand Slam semi-finalist in history.
She said: "I really cannot believe it. I would never believe I could reach the semi-final before this tournament. I am so happy and grateful.
"It was a very difficult time over the last year with my injuries but now everything has paid off. It is incredible, I am speechless.
"I was afraid of how I was going to play here. This is Wimbledon."