Hopman Cup: Serena Williams wins opener after coffee and bagel

World number one Serena Williams credited an on-court coffee for her recovery after she stormed back from a first set bagel to beat Italy's Flavia Pennetta in her opening match of the year at the Hopman Cup on Monday.

The 33-year-old American looked all at sea during the opening stages of the early morning match in a sweltering Perth but the caffeine hit did just the trick as her serve clicked into gear for a 0-6, 6-3, 6-0 win.

"I'm so jet lagged and Flavia played really, really well and yeah, everyone needs coffee every now and then. I needed coffee to get my feet moving," Williams said in an on court interview to roars of appreciation from the crowd.

"I wanted coffee with my bagel and whatever coffee it was, it was really good."

The 18-times grand slams singles champion is aiming for a sixth Australian Open in Melbourne later this month and is using the round robin mixed team event as preparation for the year's first grand slam.

Compatriot John Isner was taking on Fabio Fognini following Williams's win with the big-serving American duo teaming up for the mixed doubles against the Italian pair later on Monday.

The Australian Open runs from Jan. 19-Feb. 1 with Williams aiming for a first singles title in Melbourne since 2010 after early exits in recent years.

"Its been too long," she said. "Hopefully I will at least get past the quarters."

Image: Serena Williams of the United States celebrates winning a point against Flavia Pennetta of Italy during the Hopman Cup at Perth Arena.

Photo: Paul Kane/Getty Images