Inter got their first Champions League victory under Antonio Conte on Wednesday as they beat Borussia Dortmund 2-0 at San Siro.
Lautaro Martinez's goal midway through the first half and a late Antonio Candreva strike were enough to give the Nerazzurri their first win over German opposition since March 2011.
The result moves Conte's side into second in Group F, level on four points with Borussia Dortmund but ahead on goal difference, with Barcelona three points clear at the top after their 2-1 win over Slavia Prague.
Inter's positive start yielded a breakthrough 22 minutes in, when Nico Schulz played Martinez onside from Stefan de Vrij's chip over the top, allowing the striker to finish low past Roman Burki.
Dortmund began to take control of possession without threatening a swift equaliser, although Samir Handanovic made a good stop low to his right to deny the returning Jadon Sancho just before half-time.
Julian Brandt had been ineffective as the centre-forward in the absence of Paco Alcacer, but he did bring a smart save out of Handanovic after working some space in the Inter box.
The visitors were simply not doing enough in attack, though, and only a timely block from Manuel Akanji stopped Martinez from doubling Inter's lead on the break.
Sancho almost scrambled in an effort, but Marcelo Brozovic blocked and Candreva hacked the ball clear to preserve Inter's slender lead.
Mats Hummels brought down Sebastiano Esposito on the break but Martinez could not beat Burki from the spot.
Candreva made sure of no late drama, however, blasting past Burki after being played clean through by Brozovic.
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Anything but a win here would have left Inter up against it to qualify for the next round, so this was a welcome result for Conte, who continues to be questioned for his record in Europe given his domestic trophies.
The Inter boss will have been encouraged by his side's display here, especially in the first half, as they made an often-vibrant Dortmund attack look distinctly ordinary.
Candreva the key
Candreva deserved his goal - which he took in emphatic fashion - after an excellent all-round display that included a timely intervention when it looked like Sancho might equalise.
No real sign of Hazard
Thorgan Hazard rather summed up Dortmund's ineffective attack, creating next to nothing in his 84 minutes on the pitch.
Key Opta facts
- Conte has never lost a home Champions League group stage match, winning five and drawing six of his 11 such games across spells at Juventus, Chelsea and Inter.
- Martinez has now scored in four straight matches in all competitions (five goals), as many goals as he netted in his previous 26 outings for Inter.
- Sancho has become just the fourth Englishman to appear in 10 Champions League matches as a teenager after Theo Walcott (17), Trent Alexander-Arnold (12) and Jack Wilshere (11).
- Martinez became the first player to miss a penalty for Inter in a Champions League match since Adriano back in March 2006 against Ajax.
- Dortmund midfielder Axel Witsel became the third Belgian to appear in 50 Champions League matches after Vincent Kompany (51) and Daniel van Buyten (52).
Inter, who head to Dortmund on matchday four on November 5, host Parma in Serie A on Saturday. Dortmund will now prepare for the derby with Schalke on the same day.