Steelers' attempts to move clear of the bottom end of the league table failed at Guildford as they went down 3-2.
Flames came from behind and defended well against a tide of late attacks. Sheffield remain second from bottom. But if Milton Keynes Lightning win on Friday, they'll be joint bottom again.
The surprises have come thick and fast at Steelers this season.
And the move from Sheffield to Manchester Storm by Brendan Brooks - picked as a first line centre by coach Tom Barrasso - was one nobody had seen coming.
But Ewan, back in the line-up after a four-game injury absence, took his spot and that immediately paid dividends. McGrath had a hand Jordan Owens' goal at 4:26, with Rob Dowd the chief creator.
But the lead lasted only 31 seconds, Jez Lundin beating Jackson Whistle from close range.
Calle Ackered had featured in that play, and Steelers were having trouble dealing with him.
He was part of a move at 15;19 which saw Flames go ahead, Evan Janssen making it 2-1 for the home side.
Guildford had certainly shaded the first 20 minutes, with Whistle keeping them from furthering that margin.
Steelers' influence on the game was undermined by penalties, penalty killers having to bail out the team on three occasions.
But they did create opportunities with Dowd at the centre of things and Mark Matheson hitting the post. And Flames goalie Chris Carrozzi had to be on his toes to stop top scorer Josh Pitt.
But Jonathan Phillips did a captain's job, dragging his team level with an eye-catching, second goal of the season, at 37;04, ensuring a 2-2 scoreline at the second break.
Both defences were put under pressure in a firey start to the final session.
It was Steelers' that cracked, Ackered powering in at 47;16 to make it 3-2 to Flames, on the powerplay with Pitt in the box for holding.
Giant d-man Corbin Baldwin showed his commitment to keeping the lead to block McGrath from scoring.
With 77 seconds on the clock, Steelers had a powerplay and withdrew Whistle.
But another penalty for Pitt aided the Surrey side.