With time ticking down in the third period and the Cougars clinging to a 2-1 lead, Hayden Hall of the Thunderbirds tied the score at the 18:08 mark. The game went to overtime and the T-birds ended it on a goal by Nicholas Peebles.
Caleb Poitras had the Cougars up 1-0 after the second period. Hall scored an equalizer at 7:05 of the third and then Ryan Toor gave the Cats the lead again with a goal at the 12:59 mark.
The Cougars earned a point for the overtime loss.
Jaiden Jakubowski was between the pipes for the Cougars and Jonathan Mao was the goaltender of record for the Thunderbirds.
On Saturday, the T-birds beat the Cougars 4-2. In that one, Fraser Valley led 3-2 heading into the third period and Ryan Pretty gave his club an insurance goal at 12:40 of the final frame.
Nathan Prodanuk scored twice in the first period for the T-birds and the Cats replied with goals by Dylan Ilett and Miguel Marques in the second before Hall gave the home team the edge going into the last 20 minutes.
Jason Roth was the winning goaltender and Damien Knackstedt took the loss.
This season, the Cougars now sit at 5-7-0-2. The T-birds improved to 7-6-0-1.