The game then turned Chelsea's way with just over 15 minutes remaining as Kondogbia's pass back to his own goal flew over Daniele Padelli's head and into the top left corner.
It's the 2nd loss in a row for Chelsea in pre-season and Antonio Conte is not a happy man.
Inter won the game 2-1.More news: Samsung's profit may top Apple's for the first time ever
With time fast running out, Michy Batshuayi thought he had restored parity for Chelsea but his goal was disallowed for offside.
The Blues have a little more than one week to prepare for their FA Community Shield matchup against Arsenal on August 6 at Wembley Stadium, while Inter will face Spanish sides Villarreal and Real Betis before their Serie A season gets underway on August 20 against Fiorentina.
The Italy global has been linked with a switch to the Premier League champions after a single season at San Siro, but Spalletti insisted no deal has been done.More news: Luis Fonsi and Daddy Yankee Set Streaming Record
Inter sub Joao Mario should have made it 3-0 from Perisic's unselfish pass, but his low effort was saved by the boot of Courtois. Will we see him lining up against Chelsea in the Premier League next season?
While Chelsea's defensive errors will trouble Conte and Perisic's impressive display will leave Manchester United fans considering what role he could play at Old Trafford next season, this match will ultimately be remembered for Geoffrey Kondogbia's outrageous own goal.
One of the most outrageous own goals ever scored was not enough to prevent Chelsea ending their pre-season tour with another defeat.
But the easy afternoon would take a turn for the worst for the France worldwide when he attempted to stroke the ball back to goalkeeper Daniele Padelli from around 40 yards off his own line.More news: Eight Found Dead in Sweltering Truck at Walmart Parking Lot in Texas