India's Rohan Bopanna will become the oldest tennis world number one aged 43 after he and Matthew Ebden reached the Australian Open doubles semi-finals.
Bopanna and Australian Ebden beat Argentine pair Maximo Gonzalez and Andres Molteni 6-4 7-6 (7-5).
It is the first time Bopanna has reached the top of the world rankings.
"People all over the world, you know, being 40 and above, I think it's just going to inspire them in a different way," he said.
Bopanna and Ebden will face Tomas Machac and Zhang Zhizhen in the last four in Melbourne.
Bopanna became the oldest ATP Masters 1,000 champion when he and Ebden won the Indian Wells doubles title in March last season.
He turned professional in 2003 and has won one Grand Slam mixed doubles title alongside Canada's Gabriela Dabrowski at the 2017 French Open.
Bopanna credited his physiotherapist and Iyengar yoga with helping his longevity.
"I told her [physio] specifically what I needed, because I have no cartilage in my knees. It's completely worn out," Bopanna said.
"Yoga in a way not only strengthened my legs, my body, but also, I think made me calmer on the tennis court.
"It kind of really helped me focus a lot better. I don't feel rushed on the tennis court."
Bopanna will move to the top of the world rankings when they are updated on Monday. He and Ebden have the same number of points, but the Australian has played three more tournaments over the same period.
The previous oldest men's doubles number one was Mike Bryan, who was 41 years and 76 days.
Serena Williams is the oldest women's singles number one at 35, while Roger Federer is the oldest men's singles number one at 36. Novak Djokovic, who is the same age, could likely pass that record this year.
David Wagner was 44 in 2018 when he was ranked number one in the quad wheelchair rankings.
