Inter Milan survived a late Sassuolo scare and a bizarre intervention by a parachutist to win 4-3 and keep in touch with leaders Juventus in Serie A on Sunday as Stefano Pioli's first game in charge of AC Milan ended in a 2-2 draw against lowly Lecce.

Romelu Lukaku and Lautaro Martinez each bagged a brace in a seven-goal thriller to keep Antonio Conte's side second, a point behind Juventus who beat Bologna 2-1 on Saturday.

Inter Milan had led 4-1 with 20 minutes to go after Martinez had opened the scoring after two minutes in Sassuolo, adding a second from the penalty spot after 71 minutes.

Belgian forward Lukaku found the net after 38 minutes and converted a penalty just before the break despite a parachutist inexplicably landing on the pitch just as he was about to kick the ball.

The man was quickly led off by security agents as players and fans looked on bewildered. Then the former Manchester United striker slotted in to give Inter a 3-1 lead.

With the game under control Conte brought on winger Matteo Politano and midfielder Valentino Lazaro for their first appearances this season.

Then Filip Djuricic (74) and Jeremie Boga (81) hit back for the hosts, who are struggling in 17th position, to add to Domenic Berardi's first-half goal.

Inter held on for a win after consecutive defeats against Barcelona in the Champions League and Juventus in Serie A.

"Once it goes to 3-1 and 4-1, it should be over," said Lukaku who has now scored five Serie A goals in eight games.

"In the first half, we did everything well. However, we should have scored in the first 15 minutes after the restart to really kill off the match.

"The positive we take is that we got the three points, but we need to defend better than that.

"It was very important to get this win."

Meanwhile, Pioli's debut as Milan coach was spoiled by two players he previously coached – Khouma Babacar and Marco Calderoni.

Babacar cancelled out Turkish winger Hakan Calhanoglu's first-half goal, when the Senegalese forward missed a penalty but turned in the rebound after an hour in the San Siro.

Krzysztof Piatek came off the bench and scored with nine minutes to go after a Calhanoglu pull back, but Calderoni rifled in the equaliser in stoppage time.

"Tonight I suffered because of my exes," said Pioli.

"I had hoped for a gift this evening for my birthday, but I saw some good things, the team deserved a win, but it was our own fault we didn't," added the former Fiorentina coach, who turned 54 on Sunday.

Milan are in 12th with ten points from eight games. Lecce are one point above the relegation zone.

Italian Serie A results:

Sassuolo 3-4 Inter Milan

Sampdoria 0-0 Roma

Udinese 1-0 Torino

Cagliari 2-0 SPAL

Parma 5-1 Genoa

AC Milan 2-2 Lecce