Venus Williams, playing her first match since winning the Luxembourg title in October, defeated South Africa's Chanelle Scheepers 4-6, 6-2, 6-3 on Sunday to give the United States a 1-0 lead at the Hopman Cup mixed team event.
John Isner will play Kevin Anderson in the next men's singles match, with the teams playing a mixed doubles match later.
In the second match Sunday, the French combination of Jo-Wilfried Tsonga and Mathilde Johansson will face Spain's Fernando Verdasco and Anabel Medina Garrigues. Spain won its opening match Saturday over South Africa.