The big striker hit the only goal of the game 11 minutes into the second half, and even Ivan Radovanovic's sending-off wasn't enough to help the Milanese giants back into the game
Former Palermo, Brescia and Genoa striker Andrea Caracciolo struck a wonderful left-footed effort in the 56th minute to give Emiliano Mondonico’s men a shock lead, and they were able to hold on to claim the three points despite the sending-off of Ivan Radovanovic 10 minutes from time.
Inter enjoyed the best of the opening exhanges, and a magnificent early move involving four players nearly resulted in a goal for the returning Wesley Sneijder, but Samir Ujkani got down to hold his side-footed effort.
Novara were dealt the early blow of losing Hernan Paolo Dellafiore inside 15 minutes, with Michel Morganella replacing him in the already overworked visitors’ back line.
The lively Sneijder continued to ask questions of the Azzurri defence, and when he made progress down the left his cross into the middle just beat the advancing Diego Milito in the centre and flashed wide of the far post.
The Nerazzurri then appeared to have won a penalty when Santiago Garcia went right through Andrea Poli as the ex-Sampdoria man shaped up to shoot, but referee Carmine Russo somehow waved play on.
Claudio Ranieri made a change at half time, bringing on Giampaolo Pazzini for Ricardo Alvarez to give them added threat in front of goal, but in the early moments of the second half the home side could do little more to break down Mondonico’s side than they had managed before the break.
Milito got away in the left channel, but when he looked to cut inside to get a shot in he was foiled by Ujkani.
Moments later Lucio slid in to meet a right-wing cross from Sneijder, but it was cleared and Novara broke with a vengeance, freeing Caracciolo 20 yards from goal. The big striker cut in onto his left foot and unleashed a beautiful curling effort past Julio Cesar to stun the San Siro crowd.
Ranieri responded by replacing Poli and Cristian Chivu with Diego Forlan and Yuto Nagatomo as his side chased a vital equaliser, but when Sneijder got into a good position to cross he instead shot into the side netting at the near post.
As Inter got more desperate Novara’s defence seemed to become more stubborn, and Forlan could only find the Curva Nord when cutting onto his left when in a similar position to that from which Caracciolo had scored.
However, the Piedmont side were left hanging on with 10 men when Radovanovic was shown a second yellow card for kicking the ball away after Morganella had brought down Nagatomo just outside the Novara area.
Inter almost grabbed an equaliser three minutes from time when Sneijder unleashed a right-footed shot, but the Dutchman's effort bounced back off the bar, and Lucio couldn't turn home the rebound.
Ujkani then made a miraculous late save from Pazzini to ensure that Novara held on for the surprise victory.
The result leaves Inter six points off the Champions League pace in fifth position, while Novara could celebrate doing the double over their esteemed rivals, moving up to 16 points but remaining four short of Siena, who occupy the all-important 17th spot.