Juve moved second and level on points with Lazio after Milos Krasic's effort from a narrow angle went in off goalkeeper Fernando Muslera deep into stoppage-time.
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The hosts took an early lead when Giorgio Chiellini headed in a corner but Lazio, who beat champions Inter Milan last time, soon levelled through Mauro Zarate after another corner.
"This is a big step forward," Chiellini, whose coach Luigi Del Neri played for veteran Lazio boss Edy Reja way back in 1984 with Gorizia, told Sky. "We know how to suffer and then strike. To score right at the end was great."
Sixth-placed AS Roma are 10 points behind Milan after a 1-0 win over rock-bottom Bari where Francesco Totti missed a penalty before his chip set up a slightly offside Juan to score.
Sampdoria, who will find out at a hearing on Monday if banished striker Antonio Cassano can be sacked, missed the chance to keep pace with Roma when new Brescia coach Mario Beretta oversaw a 1-0 success for the strugglers against Samp.
Fellow promoted side Lecce also picked up a 3-2 victory over Chievo but stayed third-from-bottom while Brazilian striker Nene netted a hat-trick in Cagliari's 3-0 win over nine-man Catania.
INTER ADRIFT
Milan's easy victory meant they moved 13 points ahead of faltering rivals Inter in seventh, who are not playing this weekend because of their involvement in the Club World Cup.
The Rossoneri, who had already qualified for the last 16, suffered a wobble in Wednesday's home Champions League defeat by Ajax Amsterdam but Zlatan Ibrahimovic returned to the team in place of Ronaldinho at Bologna and his extra spark was key.
The Swede crossed for midfielder Kevin Prince Boateng to grab the opener on nine minutes before the Ghanaian produced a wonderful flick to release Robinho to score after 35 minutes.
Ibrahimovic then chested down and finished off Andrea Pirlo's pass in the second half, meaning Milan's three main close-season signings all scored again for the second straight league game following last weekend's 3-0 win over Brescia.
Marco di Vaio missed a penalty for Bologna late on.
Bologna's players have not been paid for weeks and the club has been put up for sale with the first team able to walk out for free in January if wages are still not forthcoming.
A group of local businessmen including the owner of coffee company Segafredo are interested and a deal could come soon.
On Saturday, Napoli moved third with a 1-0 win at Genoa.
