Chelsea suffered a second International Champions Cup defeat out of two in Singapore, going down 2-1 to a Stevan Jovetic-inspired Inter.
Stevan Jovetic scored one and made another as Inter completed a perfect International Champions Cup campaign with a 2-1 win against Chelsea in Singapore, but the game will be remembered for a bizarre Geoffrey Kondogbia own goal.
Inter had already beaten Lyon and Bayern Munich without conceding a goal in the tournament and Luciano Spalletti's men made it three out of three in humid conditions on Saturday.
Jovetic gave Inter the lead in first-half injury-time, scoring on the rebound after Thibaut Courtois saved his initial effort from a controversial penalty.
The Montenegrin teed up Ivan Perisic to drill home Inter's second from a narrow angle, but Chelsea, who started club-record signing Alvaro Morata on the left of a front three, were given a lifeline when Kondogbia somehow lobbed goalkeeper Daniele Padelli with a wild back-pass from 45 yards.
Michy Batshuayi had a goal ruled out due to an incorrect offside decision, with Chelsea's pre-season tour ending after a pair of ICC defeats in Asia - the next challenge for Antonio Conte's men being Arsenal in the Community Shield on August 6.
Inter should have opened the scoring in the second minute but Antonio Candreva delayed his shot and Courtois saved the winger's deflected effort well.
A deflected Willian effort narrowly cleared the crossbar after 27 minutes and, with Chelsea piling on the pressure, Padelli almost controlled a back-pass into his own net.
Inter were awarded a penalty shortly before the interval after Cesar Azpilicueta was adjudged to have fouled Jovetic, although the defender won the ball with his initial challenge.
Jovetic took the spot-kick himself and, although Courtois saved a poor effort low to his left, the forward reacted first to tuck in the rebound.
The Montenegro international had the ball in the net again within a minute of the restart, turning home another rebound after Courtois denied Marcelo Brozovic, although the offside flag denied him.
Perisic then doubled Inter's lead in the 53rd minute, the reported Manchester United target firing across Courtois and into the bottom-right corner after being played in by Jovetic.
Substitute Joao Mario could have made it three on the hour when Perisic unselfishly teed him up, but Courtois saved with his legs before Kondogbia's memorable impact.
Under little pressure 10 yards inside his own half, the midfielder aimed a lofted pass towards his own goal that ballooned over the helpless Padelli and nestled in the top-left corner.
The offside flag wrongly denied Batshuayi an equaliser after he finished well with four minutes to play and Inter held on to record a third ICC victory in a row.