Before there was Serena atop the women's tennis pantheon, Venus stood there. And while Serena bowed out in her semifinal match of the Dubai Duty Free Tennis Championship on Friday, Venus is still standing.

Venus Williams advanced to the finals in Dubai, knocking off Caroline Wozniacki 6-3, 6-2. All Serena Williams did was contribute to the conspiracy that the sisters try not to play each other in tournaments after losing her semifinal to lightly regarded Alize Cornet 6-4, 6-4.

As shocking as Serena's upset loss might be, Venus' comeback from an incurable autoimmune disease could be even more significant.

Venus was diagnosed with Sjogren's syndrome, a disease that causes joint pain, swelling, numbness and fatigue, in 2011. Her career nosedived as she didn't advance past the third round of any Grand Slam event since the 2011 U.S. Open.

She was a wild-card entry at Dubai, thanks to her wins there in 2009 and 2010, the last time she has played there.

The National, however, reported that a lifestyle change has gradually restored Venus' health, and now, apparently her game.

Venus, a seven-time grand slam winner, has adapted a plant-based diet, which has helped her regain her on-court prowess. She advanced to the finals of the ABS Classic in Auckland, New Zealand in December, her first in more than a year.

Now, less than two months later, she's back with a chance to win a championship.

According to The National, Venus and Serena live together, and Serena reported that the entire family - led by their mother, Oracene Price - has altered its eating habits for Venus' sake.

"Serena has been extremely supportive; my whole family has," Venus said, according to The National. "They have all changed their lifestyles for me. As a family we've gotten healthier and that's been amazing. She was extremely supportive and has just always been in my corner. No matter how tough things get for me, she's always been there, so it makes me feel better and makes me keep going."

In turn, the 32-year-old Serena drew inspiration from the 33-year-old Venus' fight and decided she could help by adopting her big sister's new eating habits. Serena stopped bring what the family considered unhealthy food into their home and learned how to cook vegan meals.

"Her story is the greatest for me," Serena said, as reported by The National. "To go through what she's going through, I probably would have hung up my rackets and just played some doubles. She has so much courage to show up week in and week out and play."