Inter captain Mauro Icardi has fired a warning to his side over their second-half performances after they almost let a commanding lead slip against Fiorentina on Monday.

Stefano Pioli celebrated his first victory as head coach as the home side secured a 4-2 win over the Viola at San Siro to move into the top eight in Serie A.

Inter raced into a 3-0 lead inside 20 minutes and Fiorentina played the second half with 10 men after Gonzalo Rodriguez's red card, but a first-half goal from Nikola Kalinic and a strike just before the hour-mark from Josip Ilicic gave the visitors hope of a stunning turnaround.

Icardi tapped in his second goal in injury time to kill off the game but the Argentine striker was nonetheless concerned by their inability to control proceedings in the second period, especially in the wake of their shock 3-2 Europa League loss to Hapoel Be'er Sheva last Thursday, when they conceded three times in the last 32 minutes.

"It was a game we needed to perform in, and we did, although we dropped off a bit in the second half in the same way as we did in Israel," he told Sky Sport Italia.

"Clearly that's something we need to work on. I think our fitness levels aren't the issue. I don't know if it's a fear of winning, either, but we need to control the situation better when we take the lead. This keeps happening."

Icardi scored twice after setting up Marcelo Brozovic to fire home Inter's opener, with Antonio Candreva also on target in an impressive attacking display in front of representatives from the club's Suning Group owners.

Icardi hopes the performance can be a turning point as they look to challenge for the top three in Serie A and justify the significant outlay on players in the last 18 months.

"They came to wish us the best and I think they'll go back to China happy," Icardi said.

"I don't know what has been going wrong this season. I've said since the summer that, individually, we have some of the best players in Serie A, but we need everyone to work as a team."