Inter Milan suffered another shock home defeat as Napoli took advantage to move up to fifth in Serie A with victory at Fiorentina.
Fresh from losing 1-0 at home to bottom club Novara last weekend, Inter's season took another turn for the worse after a 3-0 reverse against lowly Bologna at the San Siro.
Claudio Ranieri's future as Inter coach was hanging in the balance after the defeat, prompting nostalgic calls from the home faithful for former coach Jose Mourinho.
Bologna took the lead on 37 minutes when Diego Perez found Marco Di Vaio in plenty of room to his right and the veteran striker cut in past Yuti Nagatomo before shooting low past Julio Cesar.
Almost straight from the kick-off, a big mistake by Andrea Ranocchia enabled Di Vaio to double Bologna's lead. He was looking over the wrong shoulder when he chested a long ball back towards his own goalkeeper, but Di Vaio was lurking behind his other shoulder and he raced in to slot the ball past Julio Cesar.
Di Vaio almost completed his hat-trick in the 51st minute, but his shot was deflected wide of the far post.
Inter supporters' anger reached boiling point when another error by Ranocchia gifted substitute Acquafresca the ball five minutes from time and he beat both Nagatomo and Lucio before scoring low past Julio Cesar.
Napoli warmed up for next week's UEFA Champions League tie with Chelsea by enjoying a 3-0 win at Fiorentina, with Edinson Cavani scoring a goal in each half.
Cavani opened the scoring early on when he latched onto Marek Hamsik's neat pass and slotted the ball past Artur Boruc.
It was almost 2-0 when Christian Maggio, unmarked in the area, got on the end of Lavezzi's corner and sent a header thumping against the bar.
And the woodwork at the other end was then rattled as Cesare Natali headed a Juan Vargas corner against the post.
Napoli grabbed a second 10 minutes after half-time thanks to the same combination who provided the first as Hamsik played another good pass and Cavani took advantage of some uncertain defending to beat Boruc again.
Boruc saved well from Goran Pandev as full-time neared, but he could do nothing three minutes into stoppage-time to deny Lavezzi, who finished from outside the box for number three.