Balogun was making his first start for Monaco after joining from Arsenal and had his first spot kick saved by goalkeeper Marcin Bulka in the 12th minute. The striker got a second chance in the 56th, but again only managed a low penalty that was Bulka was able to parry.
Monaco then paid the price when Jeremie Boga burst forward in the first minute of added time and broke into the area before holding off a defender and slotting a shot inside the far post to hand Monaco its first loss of the season.
Monaco manager Adi Hütter offered his support for Balogun after the final whistle.
"Today he was unlucky and he wanted to score this second penalty," he said at a news conference, according to the club's website. "It's football. We will be there to help him bounce back because he is still a young attacker. But we win and we lose together."
Balogun, who featured for England at youth level and was also eligible to represent Nigeria, had a one-time switch to represent the U.S. approved by FIFA in May of this year. The 22-year-old has scored two goals in four appearances for the USMNT.
Balogun scored his first goal for Monaco last Sunday after coming from the bench in his team 2-2 draw at Lorient.
The Associated Press contributed to this report.