Wales' attacking threat was seen as they crossed for three tries, Jonathan Davies's effort adding to earlier tries from Lions duo Shane Williams and Mike Phillips.
But it was the Welsh defence which pleased prospective Lion Warburton the most.
The flanker, who looks nailed on for a seat on the plane for the 2013 tour to Australia noted his side's tackling as one of the keys factors to the win.
"It was a massive performance, we knew they had a lot of big ball carriers and there was a lot of tackling stopping them on the gain line," he said.
"They are dangerous, it was a fantastic defensive effort."
Warburton reckons Wales' bright start to the game was decisive in booking a place in the last four for the first time in 1987.
"We always say we don't start good enough, and we started perfectly today and it was just what we wanted," said Warburton.
"It's easier to be ahead of the game than chasing it. It's a massive achievement and we have worked so hard."
After their quarter-final 'Nightmare in Nantes' at the hands of Fiji halted their progress in France four years ago, Warburton, is now aiming to lead Wales to their first final appearance.
"The team in 1987 did it [reached the last four] and got third place" he said.
"But we have the semi next week, the boys are thrilled and it's a massive achievement, it's brilliant."