The loss puts ECFC at a 3-2 record and tied for seventh in the league of 20 teams.
The Nitros struck first as Olivia Smith scored off a penalty kick in the 13th minute to gain the lead.
Toronto extended their score early in the second half as Morgan Fenton crashed the net and scored off a pass to net the second goal in the 48th minute.
Electric City quickly responded seven minutes later as Kayla McQueen scored off a fast break to put Peterborough on the scoreboard. The goal was McQueen’s team-leading fifth goal of the season and fourth-leading in the league.
"Something like that uplifts your whole team and it gives you another push to go forward and that's really what we needed at that moment.,” said Hailey Walsh, ECFC midfielder.