TURIN, Italy — Massimiliano Allegri does not have Carlo Ancelotti’s three Champions League titles or his seemingly limitless payroll or his squad of stars like Cristiano Ronaldo and Gareth Bale and Toni Kroos.

What Allegri does have, at least for the moment, is a lead. Allegri’s Juventus, unlikely underdog in a Champions League semifinal round full of juggernauts, outplayed Ancelotti’s Real Madrid on Tuesday night, beating the Spanish giants by 2-1 in the first leg of their two-game aggregate series.

The return match will be played next Wednesday in Madrid.

On that night, Allegri may well have his players bundled together and trying to hang on. On Tuesday, however, he saw them move the ball with verve and energy as Carlos Tevez created the first goal and scored the second in a victory that has fans of the Old Lady, as Juventus is known, fantasizing about the club’s first European final appearance since 2003.

“We played with extraordinary intensity,” Allegri said. “This is deserved.”

For Ancelotti, the evening was disappointing but not a total loss. With away goals serving as a tiebreaker should aggregate scores end equal, Real Madrid’s goal here means that Los Blancos need only to win by 1-0 at home to advance and try to become the first club to win back-to-back Champions League titles. Given Madrid’s considerable firepower, that is hardly unreasonable.