Inter suffered a 3-1 defeat in Germany at the hands of Eintracht Frankfurt.
The Nerazzurri tested out two different tactical systems at the Commerzbank Arena with 50,000 fans present, as the Bundesliga begins next week.
They started out with the usual 3-5-2 and Samir Handanovic needed a stunning early save on Lanig’s header from point-blank range.
Soon after, Inter took the lead through Ruben Botta, who tapped in at the end of a fine team move between Yann M’Vila, Joel Obi and Yuto Nagatomo.
It lasted only 120 seconds, as Lucas Piazon pounced on a defensive error to go clear on goal and he scored at the second attempt, his first coming off the upright.
Haris Seferovic turned the game around completely, drilling in from 12 yards.
The Nerazzurri back three looked shaky again, as Valdez nodded a free kick on to the crossbar and Haris Seferovic reacted quickest to the rebound for his second goal in six minutes.
Walter Mazzarri switched to a 4-3-2-1 system for the second half with numerous substitutions, putting Danilo D’Ambrosio and Dodo as full-backs.
Juan Jesus needed a sliding tackle to stop Inui scoring, but there were fewer scoring opportunities. Botta wasted a promising counter-attack and D’Ambrosio tested the goalkeeper from distance.
Handanovic prevented Eintracht getting a fourth with a late save on Flum.
Eintracht 3-1 Inter
Scorers: Botta 24 (I), Piazon 26 (E), Seferovic 32, 38 (E)
Eintracht Frankfurt: Trapp; Ignjovski (Chandler 59), Anderson (Madlung 78), Zambrano, Djakpa (Oczipa 78); Hasebe (Flum 72), Lanig (Russ 59); Piazon (Kinzombi 83), Valdez (Kadlec 59), Inui (Rosenthal 72); Seferovic (Gerzigher 83)
Inter: Handanovic; Ranocchia (Guarin 46), Vidic (Andreolli 73), Juan Jesus (Silvestre 81); Jonathan (D’Ambrosio 46), M'Vila (Krhin 46), Kovacic (Hernanes 59), Obi (Laxalt 46), Nagatomo (Dodo 46); Botta, Icardi