|9. Rochdi Benzouien (Belgium)|
The two sides will meet in Sunday's Final, with Hungary and Sweden battling for bronze and the third promotion spot.
Montenegro trailed Sweden for much of their contest and were still behind 44-41 with 3:27 to play in the third quarter.
That's when Djordjije Pavicevic's side made its move.
Aleksandar Novosel hit a three-pointer to tie it and after Petar Popovic split a pair of free-throws to put them in front, Novosel struck again with another jumper for a 47-44 lead with 10 minutes to go.
With 5:49 to play, Montenegro were clinging to a 56-54 advantage after a three-ball by Sweden's Andreas von Uthmann.
Popovic, who is averaging 19.1 points per game, led Montenegro with 21 while Ludvig Hakanson and Von Uthmann poured in 19 apiece for the Swedes.
Belgium had their biggest lead of the game at 45-36 with less than three minutes to go but had to hold on at the end.
Twice the Hungarians closed the gap to three points.
Patrik Hódi's jumper reduced the arrears to 45-42 with 2:02 to go.
Then with 15 seconds to play, Csanád Antóni hit a jumper to close the gap to 48-45.
After Belgium's Rayan Kayembe-Milongo answered with two free-throws to stretch the advantage back to five, Antóni connected from the arc again with just three seconds remaining.
That's how it finished with Belgium celebrating a famous victory.
In Classification Round games, Denmark romped to a 95-49 victory over Switzerland, Israel defeated Portugal 73-64, Romania edged Bulgaria, 76-70, Bosnia and Herzegovina beat F.Y.R. of Macedonia, 79-69, Belarus overcame Georgia, 74-66 and the Netherlands pulled away from Finland, 76-59.