Juventus paid the price for resting Cristiano Ronaldo, as their unbeaten start to the season suffered a shocking end at Genoa.
The Serie A champions lost 2-0 on Sunday.
Ronaldo was left out of the squad, following his hat-trick against Atletico Madrid in the Champions League in midweek.
After a goalless opening 45 minutes, former Juve midfielder Stefano Sturaro struck in the 72nd minute to open scoring.
Goran Pandev added the second with nine minutes left.
Juventus could now see their lead at the top slashed to 15 points, should Napoli defeat Udinese later today.