Brossoit now has five assists in his WHL career with his previous three all coming in the 2011-12 campaign.
Michael St. Croix had a goal and an assist for the Oil Kings (4-2-0), who won for the first time in three outings, while Travis Ewanyk, Dylan Wruck and Brandon Baddock had a goal apiece.
Darren Dietz had the lone goal for Saskatoon (2-5-0-0) while Andrey Makarov turned aside 31 shots in a losing effort.
Edmonton took advantage of Saskatoon's struggling penalty kill by going 3-for-5 on the power play. The Blades have now given up eight power-play goals on 10 opportunities in their past two games. Saskatoon went 1-for-9 with the man advantage.
The Oil Kings opened up the scoring with three straight power-play goals in the second period.
Ewanyk started the offence at 4:21, shovelling in a rebound past Makarov.
Two minutes later Edmonton's scoring leader St. Croix kicked a pass from Henrik Samuelsson up to his stick and tapped it in.
Wruck quickly followed to make it 3-0 Edmonton.
Just over five minutes into the third, Braddock put Edmonton up 4-0 with a wrist shot through traffic.
Dietz halted Brossoit's bid for his first shutout of the year with a rocket shot on the power play 1:43 later.