The Owls emerged triumphant from their penultimate game of the season, beating Cardiff 1-0 in the Welsh capital.
Ryan Croasdale scored the only goal of the game in the 91st minute to give Wednesday a deserved three points.
The visitors fielded a significantly younger squad, which made the victory all the more impressive, said coach Lee Bullen:
“I couldn’t be more pleased for the boys because it was a very young side we put out there today.
“We played without fear against a very good side and as the clock was ticking down, I thought it was heading for a 0-0, which in itself would have been a good result.
“But we got the winner through Ryan Croasdale right at the last and we thoroughly deserved it.”