UDINE - Inter took a step closer to a fourth consecutive Serie A title after Sunday's 1-0 victory over Udinese.
The home side dominated for much of the ninety but the Nerazzurri got the all-important goal with 13 minutes remaining when Isla turned into his own net.
Sunday's fifth straight away win sees Inter take full advantage of Juventus' 3-3 home draw against Chievo and open up a nine-point gap with eight games left to play.
Gökhan Inler fired an early warning when his crisp 20-yard strike forced Julio Cesar into a punched save.
Inter soaked up the early pressure and Muntari had two chances on his old stomping ground, firing just wide on both occasions.
Quagliarella had a penalty claim turned down before sending a swerveshot wide as Udinese imposed their game in the ten-minute period before the break.
Udinese brought their momentum into the second half and Floro Flores had a weak header saved before he set up Inler who sent a terrific shot just wide of the target.
Ibrahimovic forced a save from Belardi with a low 20-yard shot as Inter struggled to find openings, and the Nerazzurri had Julio Cesar to thank for a brilliant tipped save from Quagliarelli, moments before Felipe sent wide a flicked header from Pasquale's cross.
Inter produced a further chance when Stankovic slid wide from close range after Ibrahimovic's right-wing cross.
With time running out Mourinho made a double substitution. Opting for experience over youth, he introduced Figo for Balotelli and Vieira for Santon.
The Portuguese was forced into a third switch soon after, bringing on Toldo for Julio Cesar who pulled up with a thigh injury.
The breakthrough came in the 77th minute when Vieira beat the offside trap to collect Ibrahimovic's pass and Udinese defender Isla turned the ball into his own net.
Ibrahimovic went close to what would have been a magnificent second goal in added time, drifting past three players before shooting narrowly wide of the far post.
Udinese 0-1 Inter (HT: 0-0)
Scorers: Isla (o.g.) 77.
Udinese: 80 Belardi; 15 Isla, 2 Zapata, 19 Felipe, 26 Pasquale; 88 Inler (5 Obodo 83), 21 D'Agostino, 20 Asamoah; 7 Pepe, 27 Quagliarella, 83 Floro Flores (9 Ighalo 84).
Subs not used: 12 Koprivec, 18 Zimling, 65 Sissoko, 66 Bradaschia, 99 Sala.
Coach: Pasquale Marino.
Inter: 12 Julio Cesar (1 Toldo 73); 39 Santon (14 Vieira 69), 2 Cordoba, 26 Chivu, 6 Maxwell; 4 Zanetti, 19 Cambiasso, 20 Muntari; 5 Stankovic; 8 Ibrahimovic, 45 Balotelli (7 Figo 69).
Subs not used: 9 Cruz, 18 Crespo, 23 Materazzi, 25 Samuel.
Coach: José Mourinho.
Referee: Luca Banti (Livorno).
Booked: Quagliarella 22, Maxwell 41, Vieira 70, Pepe 78.