France will host Belgium in the final of the Davis Cup mens teams tennis competition later this year.
Belgium came back from 2-1 down to beat Australia in Brussels.
Australia had the overnight lead but world number 12 David Goffin narrowly overcame 20th-ranked Nick Kyrgios 6-7 (4-7) 6-4 6-4 6-4 as Belgium levelled.
Steve Darcis then beat Jordan Thompson 6-4 7-5 6-2 for victory.
France booked their place in the final when Jo-Wilfried Tsonga beat Dusan Lajovic to give them an unassailable 3-1 lead over Serbia.
France, who have won the championship nine times, will host Belgium, who were runners up in 2015, in the finals in November.
"It's a big win for me and a big win for us," said Belgian Darcis.
"David [Goffin] did an unbelievable job for us today. I have never seen him play as well as this and I'm really happy I could finish it off."
Yannick Noah's French side needed only one singles match on Sunday to see off a Serbian side who were without Novak Djokovic.
Underdogs Serbia had picked up an unexpected first point when Lucas Pouille lost to Lajovic in Friday's singles but Tsonga levelled by beating Davis Cup debutant Laslo Djere.
Pierre-Hugues Herbert and Nicolas Mahut then beat Filip Krajinovic and Nenad Zimonjic in the doubles and Tsonga's second victory saw them progress.
Meanwhile Davis Cup holders Argentina were relegated from the world group when they lost 3-2 to Kazakhstan in Astana.
The Argentines, who won their first title 10 months ago, were without leading players Juan Martin del Potro and Federico Delbonis and will play in the Group One Americas zone next year.