The Bavarians ran out 4-0 winners at the Allianz Arena in their semi-final first leg clash thanks to a Thomas Muller brace plus goals from Mario Gomez and Arjen Robben.
Bayern have already wrapped up the Bundesliga title and following Tuesday night's dominant display are well-placed to progress to a third Champions League final in four years.
"Obviously, a victory like that takes time to sink in," Lahm told Bayern's official website.
"This team has the potential to hurt even the likes of Barcelona. That's half the job done.
"We'll have to work just as hard next week, especially in defence. That was the key to victory. We pulled everyone back behind the ball and prevented them making chances. And we looked very good on the ball in attack."
Bayern club president Karl-Heinz Rummenigge was in no mood to play down his side's achievement as they dismantled a Barca who are looking to win their fourth Champions League title in eight years.
"The team were fantastic," said the two-time former European Footballer of the Year. "I've never experienced an evening like that, and I've been in the game a long time. We've won 4-0 against the best team in the world, it's like a dream come true.
"It went perfectly for us. We go to Barcelona with every chance now. The strength of this team is the performance as a collective. Barca can rarely have created so few chances. A huge compliment to every man on the team."
Barca superstar Lionel Messi conceded it would be a tough task for his side but is hopeful of a change in fortune this weekend.
Tito Vilanova's side can win the Primera Division title if they beat Athletic Bilbao and second-placed Real Madrid slip-up against city rivals
Atletico and Messi believes domestic success could be the catalyst for a European fightback next week.
He told reporters: "It's difficult to fight back, but we'll try to score the goals we need at the Nou Camp. We have to pick ourselves up, finish off La Liga and try to come back against Bayern.
"It will be very difficult game in the Nou Camp, to come back from 4-0 down, but we need to take it to them and try to achieve it. The are very good but we will try," he said.
After picking up a hamstring injury against Paris St Germain in the last round, the Argentinian sat out Barca's last three league games and on his return on Tuesday night was unable to create much of an impact against last year's Champions League runners-up.
He said: "I'd gone a while without playing since the injury, but I felt well.
"We will lift ourselves again, we need to win the league, where there are four games left, and try to turn things round in the Champions League, and if we can't then we will need to think about next season."