Fridolina Rolfo's second-half goal took Wolfsburg through to a fifth Women's Champions League final as they beat Barcelona 1-0 in San Sebastian.
The Sweden striker pounced as the ball came to her from Ewa Pajor's attempted overhead kick, settling a tight match.
"We were a little bit lucky but I'm so proud that we did it," Rolfo told BT Sport.
Wolfsburg, twice Champions League winners, will face Paris St-Germain or Lyon in Sunday's final (19:00 BST).
The two French sides meet each other in the second semi-final in Bilbao on Wednesday.
All ties from the quarter-finals onwards in this season's competition are being played as one-off matches behind closed doors in Spain to reduce the risk of spreading coronavirus.
Victory for Wolfsburg on Sunday would complete a treble, as they have won the Women's Bundesliga and German Cup this season.
Barcelona, Champions League runners-up last year, started the brighter of the two sides and had a penalty appeal waved away in the first half.
The ball appeared to strike Wolfsburg defender Kathrin Hendrich after a free-kick was swung into the Barcelona box.
But the referee failed to spot the handball, with the video assistant referee system unable to intervene as it is not in operation until Sunday's showpiece.
The Spanish league champions had 16 chances during the game but it was Wolfsburg, who demolished Glasgow City 9-1 in the quarter-finals, who opened the scoring through Rolfo.
The matchwinner said: "It says a lot about the club that everybody wants to win and has a strong winning mentality, even if we didn't play our best today."