Complex sentence: Valetti had a lead of a minute and a half after that stage and built upon that as the Giro went on, finishing almost nine minutes ahead of the second place rider Ezio Cecchi.
Split into simpler sentences: Valetti had a lead of a minute and a half after that stage, but he built upon his lead as the Giro went on. He finished almost nine minutes ahead of the second place rider Ezio Cecchi.