Serena and Venus Williams are back on top of the world. More than 15 years after the history-making sisters blew into the women's game with hurricane force, they are still putting their rivals, many of them 10 years younger, to shame.
When the new WTA rankings are released on Monday, Serena will remain number one while Venus climbs back to second.
The Florida pair last stood together at the summit from May 5-11, 2003, with Venus dropping to third on May 12 to end that brief duopoly.
In between, Serena and Venus, who turned pro in 1995 and 1994 respectively, have watched the generations come and go, with the rise of the Russians, Serbs and Belgians.
But despite fluctuations in their rankings - Serena won the 2007 Australian Open after finishing the previous season standing 95th and having played only four events in 2006 - their staying power has been phenomenal.
Venus assured her rise from fourth to second behind her sibling by reaching the third round of this week's Madrid Masters, a tournament which saw Serena exit at the same stage.
"In the rankings, you keep going until you get to that number one spot," said Venus, who will be 30 in June and is the second oldest player in the top 50.
"Serena and I being number one and number two in the world is what we dreamed of growing up. But we each dreamed of being number one - neither of us dreamed of number two.
"I congratulate Serena on her ranking but I'm aiming to get there myself."
The pair have spent a total of 45 weeks in the leading positions.
The first four came between June 10-July 7, 2002 (Venus one, Serena two); the next 40 came between July 8, 2002-April 13, 2003 (Serena one, Venus two) and the last was May seven years ago.
"We can definitely celebrate," said Serena, whose Madrid run was ended in the third round by Nadia Petrova. "It's a great feat to be back at one and two.
"It's so amazing and it's a moment that we can always hold no matter what. We can always have this moment again."
Both sisters will be building focus for the May 23 start at Roland Garros, which 12-time Grand Slam champion Serena won in 2002 over her sister.
Recent Paris outings have been less successful, with Venus stalling in the third round for the last three editions and Serena a quarter-finalist in two of the last three years in the French capital.
For Serena, at least a few days this week will be spent at her flat in Paris, with Venus surely a welcome guest if required.
Serena said that she hopes to rid herself of accumulated stress, despite playing only her fourth event of 2010 after dealing with various knee problems in the three months since winning a fifth Australian Open.
"When you play matches, it's totally different than practise," she said. "Getting that match play, you put your body under different levels of stress.
"I feel like I've been under different levels of stress, and hopefully within the next week and a half I'll be better."