WASHINGTON, March 13 (Xinhua) -- After watching the Williams sisters play their 29th clash of their careers in Indian Wells, ATP world No.1 Roger Federer has praised the performance of Venus and Serena, saying they showed "longevity and dominance".

"They had a massive arrival on the scene, a lot of buzz around them, and they lived up to the hype, came out and crushed it," Federer was quoted by the WTA official website as saying on Tuesday.

Venus and Serena faced each other in the third round of the BNP Paribas Open at Indian Wells on Monday night, with the older sister coming out on top 6-3, 6-4.

Both have dealt with illness and injury to maintain their careers at the top, another achievement admired by the Swiss mogul.

"For many years we were worried that they were going to check out early with sickness or injuries. We weren't sure if they're going to play as long as we hoped them to play," he said.

"And here we are. They are both over 35, 36, and still basically playing at the top with Serena being a mom now and Venus overcame a lot of also difficult situations and still playing."

He added that he hoped Serena would continue to combine tennis and motherhood successfully, saying: "I think that's going to be a huge story, maybe the story of the year. Hopefully she decides to play a lot and enjoy herself in the process and get back to who knows how high? It almost doesn't matter, but it would just be amazing to see her do it now."