Alonso’s Ferrari team-mate Brazilian Felipe Massa was fifth ahead of Briton Lewis Hamilton of McLaren.
Finn Kimi Raikkonen was seventh for Lotus ahead of Mexican Sergio Perez of Sauber, Australian Mark Webber of Red Bull and Venezuelan Pastor Maldonado of Williams.
Schumacher was one of a number of drivers who hit the bumps at the Variante Alta.
He was not the only man to do so during the session, with Raikkonen, Germany’s defending drivers champion Sebastian Vettel of Red Bull, Webber, Massa and F1 rookie Ma Qing Hua of China, driving for the Hispania team, among others to smash over the kerbs at the first and second chicanes.
Hua, the first Chinese-born driver to take part in an official F1 session, had stepped in for Indian Narian Karthikeyan and made a solid effort in his first appearance, cutting five seconds from his early times to get within two of team-mate veteran Spaniard Pedro de la Rosa, taking part in his 100th Grand Prix, by the end.
Vettel could not quite break into the top 10. He was just four thousandths slower than Maldonado, while Lotus sub Belgian Jerome D’Ambrosio was 15th, just over a second slower than Raikkonen, as he made a cautious start as replacement this weekend for the suspended Frenchman Romain Grosjean.