Even before the puck dropped for the opening face-off, Mitchell was playing from behind.
The team's line-up suffered a number of scratches due to injuries and illness.
Captain Malcolm Mcleod, Carter Lewis, Sean Chisholm, Jameson Mitchell, and Jared Lesouder were all scratches.
Tyler Parr would start in the net but faced a lot of pressure, especially in the second period.
After taking a 1-0 lead in the first period on the power play, Stayner jumped ahead in the second.
The Siskins put 29 shots on the Mitchell net in the second period and scored four goals.
The barrage continued in the third, with 19 more shots and three more goals.
The final was 8-0 in favour of Stayner and the visiting team put a total of 59 shots on net.
Game 2 will be played in Stayner at 2:30 p.m. Saturday and CKNX AM 920 will have the call.
Across the other PJHL conferences, New Hamburg beat Grimsby 3-1, Lakeshore beat North Middlesex 2-0 and Clarington beat Napanee 3-2 in overtime.
All three games were the opening game of the series.
