Serena Williams
Serena Williams (C) of the U.S. is helped as she leaves the court after retiring from her second round match against France's Alize Cornet at the Wuhan Open Tennis Tournament in Hubei province September 23, 2014. World number one Williams withdrew from the Wuhan Open on Tuesday after falling ill midway through the first set of her second round match against Cornet. The American top seed was leading 6-5 after breaking Cornet's serve with a smash only for the doctor to come on court at the change over and take the 32-year-old's temperature. Reuters

World number one Serena Williams recently hosted a charity marathon event in Miami, Florida. The 33-year-old 18-time Grand Slam champion also took part in the event and even entertained the crowd when she belt out a song on stage after the short marathon.

Mail Online has obtained exclusive photos from the event on Dec. 14. Serena was seen sporting a black Nike outfit. She had short shorts and zip-up jacket. She completed her ensemble with a black Nike headband. Serena's older sister Venus also joined the fun run. Venus was wearing a pink top and a pair of Capri pants.

Serena was delighted with the support that she received from everyone who supported the fun run. She took to Twitter and Instagram to thank the people who showed up.

People from all races are showing support

— Serena Williams (@serenawilliams) December 14, 2014

"Made it," she wrote on Instagram. "Thank you so much to our volunteers, sponsors, runners, and fans who made today so special, see you next year @theultimatum #serenawilliamfund."

In a news article by Florida-based newspaper Miami Herald, it has been said that the charity event, which included The Quarter Marathon, a 5K Run/Walk, and Ultimate Kids Dash will benefit Serena's foundation, which helps underprivileged school children in Kenya and families affected by violent crimes.

Serena revealed that she got the idea of hosting a charity marathon event after she participated in a 5K event in Palm Beach. She said that she takes part in a 5K or 10K run every year to begin her training.

"Last year, after running the 5K, I thought, 'Wow, I really should do my charity based on running because it's a really fun way to promote a healthy lifestyle," Serena said. "People love it - you can run, walk, bring your family."

According to Serena she has started running 10 years ago. She said that it has helped her take full advantage of her stamina on the tennis court. Serena added that she doesn't want kill herself by running in long distances. She prefers 5K because it doesn't tire her that much, but she can still feel the marathon atmosphere.

After the race, Serena and Venus hit a few notes by singing the classic upbeat song "We are Family" on stage. TMZ Sports has the video of Serena belting out after the race.

Serena's foundation was established to provide assistance to the youth, parent, and families who have been victims of violent crimes. Her foundation builds programs to give counseling, care, housing, food, and education to deprived and neglected people. It also provides scholarships to children all over the world.

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