Steve Darcis has proved to be Australia's Davis Cup nemesis yet again as Belgium sealed a place in November's final against France with a 3-2 win in Brussels.
On a hugely disappointing day for captain Lleyton Hewitt, the host nation clinched the two reverse singles rubbers, with Darcis beating late replacement Jordan Thompson 6-4 7-5 6-2 in the decider.
Earlier, an inspired David Goffin produced one the best performances of his career to come from a set down to beat Nick Kyrgios in four sets.
It is the second time Darcis has broken Australian hearts in a deciding rubber after his victory over Carsten Ball in Cairns seven years ago relegated the 28-time winners from the World Group.
Feasting off the energy of a delirious home crowd at the Palais 12 arena, Darcis broke Thompson - who was drafted in by Hewitt at the last minute instead of original selection John Millman - in the very first game as he broke the Sydneysider.
The wily world No.77 took out the first set in 40 minutes and fought magnificently to win the second - staving off a set point with an ace after earlier holding serve following a titanic 49-shot rally.
He then broke Thompson twice early in the third and cruised to victory as Belgium reached the final for the second time in three years.
World No.12 Goffin had never beaten Kyrgios in their three previous encounters and was on the back foot in the opening set against the Canberran's serve.
However, the Belgian held firm to save seven break points in the first three games and keep the scores level before Kyrgios won the tiebreaker with a 204kph missile.
But Goffin, who has only tasted defeat to Andy Murray in a singles rubber since 2014, responded magnificently, nailing his first break point of the match in the opening game of the second set.
Confidence restored, the 1.8m baseliner started to find his range with some crunching returns to level the match at 1-1.
The third set followed a similar trend as Goffin took a 2-1 lead.
A frustrated Kyrgios at one point in the fourth set shrugged to the Australia bench and mouthed "I am not doing anything wrong," after another brilliant winner from Goffin.
The 22-year-old hit back after a break to level at 4-4, but immediately handed back the initiative with a double fault at 30-40 and Goffin served out for the win.
Kyrgios admitted there not much more he could have done to stop the 1.8 metre baseliner, who has now won 15 of his last 16 Davis Cup singles rubbers.
"When he is playing at that level he is up there with the best in the world," Kyrgios said after the 6-7 (7-4) 6-4 6-4 6-4 loss.
"He served unbelievably well today. He was moving great, hitting great. He was too good."
Despite hurling down 24 aces and more than playing his part in a high-quality encounter, Kyrgios said not converting his chances cost him.
"I thought I started the match really well, I had a couple of opportunities early and could have been up three or four love up," he said.
"It was a tough match but he played at a pretty high level, I thought the match in general was a pretty high level. It was too good by him today.
"He was too good today and better as a whole.
"But we win as a team we lose a team."