Roberto Mancini believes Italy's first-half performance against Belgium was "below expectations" and proved costly in their Nations League clash.

In their first match since Mancini's return to the helm, Italy lost 2-0 to Belgium at Stadio Olimpico after goals from Mika Godts and Dodi Lukebakio either side of half-time.

Italy have lost a home match while conceding at least two goals without scoring any for only the second time in the last 40 years, after a 2-0 defeat in a friendly against Croatia in August 2006.

The Azzurri ended the match with 1.5 expected goals (xG), though only 0.3 of their tally came in the first half, while Belgium accumulated 2.5 of their 2.7 xG before the break.

Gianluigi Donnarumma made six saves to try and inspire a comeback for Italy, but Senne Lammens also made six saves at the other end to keep Belgium in front.

While Mancini acknowledged Italy's improvements after the break, he admitted their first 45 minutes were not good enough.

"Belgium played better in the first half, we took the initiative in the second and could've equalised, but we conceded on a counter-attack with our error. This is football," Mancini told RAI Sport.

"The first half was below expectations, as Belgium played better, but not the second half.

"The team did really well until that second goal. We had four or five chances to equalise, we pinned them back, but Belgium are a strong side."

Italy, who have failed to qualify for each of the last three World Cups, were jeered off the pitch at full-time in Rome.

Riccardo Calafiori was "hurt" by the reaction of the fans and has urged his team-mates to focus on the positives from the defeat.

"They hurt, because at times I felt the passion of the crowd. We've got to do better, we all know that, starting from the next match," said Calafiori, who won possession eight times and created three chances.

"I saw a good team in fits and starts. We've just started working with a new coach, but other areas I didn't like, we left gaps and conceded two avoidable goals. We must try to look at the positive aspects.

"There is a lot of work to do, we've just started with a new coach, so we'll see."