After three home games unbeaten, Udinese were beaten at Bluenergy Stadium by league leaders Inter.
Lautaro Martinez's goal after 20 minutes proved to be the difference, despite a late rally by Kosta Runjaic's men.
The result leaves Udinese in tenth place on 26 points.
Udinese 0-1 Inter (HT 0-1)
Scorer: Martinez 20.
Udinese (4-4-2): Okoye; Kristensen, Kabasele (Bertola 74), Solet, Kamara; Zanoli (Ehizibue 74), Piotroswki (Miller 44), Karlstrom (cap.), Ekkelenkamp (Bayo 84); Atta (Gueye 74), Davis.
Subs not used: Nunziante, Sava, Padelli, Goglichidze, Lovric, Zarraga, Camara, Zemura, Modesto.
Coach: Runjaic.
Inter (3-5-2): Sommer; Bisseck, Akanji, Carlos Augusto (Acerbi 77); Luis Henrique, Barella (Sucic 88), Zielinski, Mkhitaryan (Frattesi 77), Dimarco; Esposito (Bonny 67), Martinez (cap.) (De Vrij 88).
Subs not used: Calligaris, Taho, Thuram, Diouf, Darmian, Cocchi, Bovo, Bastoni.
Coach: Chivu.
Referee: Di Bello
Assistants: Bercigli, Zingarelli
Fourth official: Feliciani
VAR: Mazzoleni
AVAR: La Penna
Booked: Carlos Augusto 70.
Added time: 2+4 minutes.
Matchday tickets: 14,844 (€1,141,038)
Season tickets: 10,085 (€122,593)
Total attendance: 24,929 (€1,263,631)