Inter's desire to "win at all costs" against Napoli helped them to end the Serie A leaders' unbeaten start, explained head coach Simone Inzaghi.
Napoli had won 11 straight Serie A games prior to the World Cup break as they headed into Wednesday's meeting with Inter at San Siro holding an 11-point lead over their hosts.
But a superb performance from Inzaghi's men was capped with a 56th-minute headed winner from Edin Dzeko as Inter picked up valuable points in their hunt for a 20th Serie A title.
Inzaghi was delighted with his team's display after the game, and cited their resolute mentality as a key reason for the 1-0 victory.
"Inter were organised and wanted to win at all costs," Inzaghi told reporters. "I have to congratulate the guys on the pitch, they helped each other with haste and determination.
"Tonight I bring the happiness of the victory to dedicate to the fans."
Inzaghi chose to start a front two of Dzeko and Romelu Lukaku, before the pair were replaced at a goal up by Joaquin Correa and returning World Cup hero Lautaro Martinez.
The Inter head coach is a big fan of the options he has in attack, saying: "There are four, my wish is to have them all available. I have some intelligent boys. Playing every three days, I will have the opportunity to change it."
Inzaghi hoped the victory over Napoli would spur his team on as they look to close the eight-point deficit to the summit, having now won three consecutive Serie A matches.
"We must continue like this," Inzaghi told DAZN. "Tonight is a great injection of confidence.
"I'm proud of my boys, it's a pleasure to see them like this. We had a great match but we have to continue like this.
"In the league we lost points initially, but it's still a long way [to go]. We have to think match-by-match."
Napoli have scored a league-leading 37 goals this Serie A season, but they were restricted to just two shots on target by Inter as the likes of Victor Osimhen and Khvicha Kvaratskhelia were kept quiet.
Partenopei head coach Luciano Spalletti lamented his side's poor attacking output at San Siro, saying at his post-match news conference: "We were below all our offensive qualities.
"We can do more both as an offensive department and how to prepare the offensive department for important plays. We passed the ball around well in some stretches, but we were not very incisive.
"We need more personality and strength, we have these qualities. I didn't like the fact that we were shy in some moments."