Despite Thiago Motta's first half red card, Inter beat Celtic 2-0 with Luc Castaignos and Giampaolo Pazzini in the Dublin Super Cup.
The Nerazzurri welcomed back Luca Castellazzi after a head injury to defend the goal against the Hoops and put in an excellent performance. Earlier today, Manchester City had beaten an Irish XI 3-0 with teenage Italian trialist Luca Scapuzzi netted the final goal.
Gian Piero Gasperini rested some of his top stars ahead of Sunday's match against Roberto Mancini's City, while the South Americans are still on vacation following the Copa America.
It was not the friendliest of encounters, as there was a scuffle within six minutes between Cristian Chivu and Beram Kayal.
Moments later, Inter took the lead with their teenage summer signing from Feyenoord, Castaignos. He sprung the offside trap from a smart Goran Pandev through ball and beat Lukasz Zaluska at the near post.
Yuto Nagatomo appeared to pop his shoulder out of joint and was stretchered off for youngster Marco Faraoni. Pandev was also fortunate to escape punishment when kicking out at Kayal.
Georgios Samaras went close to an equaliser with a splendid volley, but Castellazzi fingertipped it round the post thanks to his wonderful save. Castellazzi needed a desperate double save to deny Samaras and the Mulgrew follow-up after defensive chaos.
Pazzini's fierce angled drive was palmed round the back stick by Zaluska and Castaignos prodded wide with only the goalkeeper to beat.
Inter were reduced to 10 men before half-time, as Thiago Motta was shown a second yellow card for a late kick at Scott Brown.
However, the Nerazzurri still managed to double their lead in stoppages. Pazzini took the Celtic defence by surprise on a long Cristian Chivu ball from midfield and chipped it over the on-rushing Zaluska.
Tempers continued to flare in the second half, as Du-Ri Cha and Faraoni had a scuffle. Samuel Eto'o and Wesley Sneijder came off the bench with the Dutchman again in that new central midfield position.
Understandably with a man down and 2-0 up, the Nerazzurri sat back more after the break. Anthony Stokes sprung the offside trap only to be kept out by Castellazzi's trailing foot. In stoppages, the goalkeeper flew to flap a McGrew free kick off the line.
Inter 2-0 Celtic
Scorers: Castaignos 6 (I), Pazzini 45 (I)
Sent off: Thiago Motta 44 (I)
Inter: Castellazzi; Ranocchia (Caldirola 85), Samuel, Chivu; Santon (Bianchetti 78), Stankovic (Mariga 56), Thiago Motta, Nagatomo (Faraoni 10); Pandev (Eto'o 46), Pazzini, Castaignos (Sneijder 46)
Celtic: Zaluska; Cha (Matthews 67), Loovens (Stokes 60), K Wilson, Izaguirre; Brown, Kayal, Ledley, Mulgrew; Samaras (McCourt 75), Maloney (Hooper 60)