In a see-saw contest, Cardiff led 1-0, trailed 2-1 but rallied to win with two goals in the final period from Jason Stone and Steve Thornton.
It gave Devils their fourth win in the six meetings between the sides this season and, more importantly,opened a four-point gap over Steelers at the top of the table with the season now in the home straight.
The result capped a miserable weekend for Steelers. Last season's Grand Slam winners were beaten 5-2 at home by Ayr Scottish Eagles on Saturday night, while Cardiff were picking up a useful point at Basingstoke.
Ayr boosted their hopes of claiming third place with a 5-3 win over fellow hopefuls Nottingham Panthers on Sunday, while Newcastle Cobras, who are third at the moment, slumped to a 6-3 defeat at Bracknell Bees after losing their influential player-coach, Rick Brebant, who was injured.Reuse content