When did Ridgeway slip

I'm trying to remember the year that Dave Ridgeway of the Riders slipped when attemping a last second field goal in the playoffs? I think this was in 1985 or so but cant remember or find any info, please help.

thanks

Googled it and found a post at Riderfans where a poster says it was 1990 against the Eskimos in the western final.

ahh computers, i didn't even think of that, thanks!

1992 West Semi Final in Edmonton. I was living in the USA at the time and heard about it after the fact.

Hard to believe he slipped at Commonwealth.