Hewitt, 18, capped a perfect weekend when he beat Kafelnikov 6-4, 7-5, 6-2 in the first reverse singles match to give Australia an unbeatable 3-1 lead.
"I wanted to come out here and kill him today," Hewitt said. "There's nothing better than beating a bloke who's been mouthing off all week about how he's going to beat us."
The straight-sets defeat did not stop Kafelnikov from firing a parting shot. "He's young and enthusiastic," he said of Hewitt, "but his game doesn't impress me. He doesn't create any specific situation, his serve is mediocre. He had a good day. That's it."
In the second singles, Wayne Arthurs completed the 4-1 rout when he beat Russian teenager Marat Safin 6-3, 6-2 in just 49 minutes. Russia's only win came in Saturday's doubles.
France, who had already clinched a place in the final after winning Saturday's doubles, defeated Belgium 4-1. Christophe Van Garsse achieved Belgium's only victory, beating Cedric Pioline 6-3, 6-4. In the other "dead" rubber, Fabrice Santoro defeated Christophe Rochus 7-5, 6-4.
The French, winners of the Davis Cup in 1991 and 1996, built an unassailable lead in the doubles as Olivier Delaitre and Fabrice Santoro beat the inexperienced team of Xavier Malisse and Van Garsse.
Seven others sides advanced to the World Group with qualifying-round victories: Austria, Czech Republic, Germany, Zimbabwe, Spain, Britain and Italy. Ecuador or the Netherlands will claim the other spot.Reuse content