Mikaela Shiffrin delivered an astonishing second run to overtake Tina Maze and clinch the World Cup slalom title with an improbable come-from behind victory Saturday.

The American teenager trailed Maze by a massive 1.17 seconds after the first leg and needed to finish ahead of the Slovenian to win the slalom crystal globe in her first full season on the circuit.

Shiffrin, who was fourth in the morning, had a tentative start to the second run but blazed down the bottom part of course for the fastest time of the afternoon. When first-run leader Maze crossed the line in third, Shiffrin put her hands to her face and sank to her knees in the finish area.

Bernadette Schild of Austria was second in the race, 0.20 behind Shiffrin. Maze trailed by 0.35.

Shiffrin, who turned 18 Wednesday, is the first American woman to be World Cup slalom champion since Tamara McKinney in 1984.