The Germans suffered a major setback in Group D on Saturday when they lost 1-0 to Serbia in Port Elizabeth having had striker Miroslav Klose sent off before the break.
They are currently second in their group, a point behind leaders Ghana, who provide the opposition in their final first-round game in Johannesburg on Wednesday, where defeat could prove fatal.
However, Bayern Munich full-back Lahm is certain Germany will make it to the knockout stages, just as they did at UEFA EURO 2008 after losing to Croatia.
Asked if the pressure on the players was mounting, Lahm told Welt Online: "Yes, but most of us have been in situations like this before - in 2008 at the European Championships, it was similar.
"We needed a draw in the final preliminary round game, otherwise we would have gone out of the tournament. But we made it into the next round then, and we will get there this time."