Ten-man Wednesday went down by the odd goal in three to play-off rivals Fulham as the regular season concluded at Hillsborough.
The Owls took the lead through Sam Winnall before Neeskens Kebano equalised and Marco Matias was sent off for a late challenge on Sone Aluko.
Then just as it seemed the contest was ending all square, Kebano popped up with the winner 11 minutes from time.
The Owls made ten changes for the final fixture and up front, Winnall soon made his mark.
Taking a cute ball from Kieran Lee into his stride nine minutes in, the striker fired low and hard across Marcus Battinelli to give his side the perfect start.
Jordan Rhodes sprung the offside trap moments later but just fell short of controlling a fine high ball from Liam Palmer.
Fulham looked dangerous on the counter, which proved the case on 25 minutes when the Londoners levelled.
Denis Odil crossed from the right and Kebano ghosted into the penalty area to slide past Joe Wildsmith.
The Cottagers almost burst into the lead on the half-hour when Chris Martin was inches away from converting a Tom Cairney corner before Matias was dismissed after tangling with Aluko.
Still there was time for Wildsmith to deny Martin from close range with a brave block and the curtain came down on a first half full of incident.
The second period began with a similar spark and Fulham came close to making their numerical advantage count when Scott Malone crashed against the crossbar from six yards.
Wildsmith then acrobatically kept out a Malone curler as the Cottagers turned the screw and Martin missed a sitter only for his blushes to be spared by a linesman’s flag.
Morgan Fox denied Floyd Ayite a certain goal with a well-timed tackle as Fulham continued to press.
The Owls had the next chance on 69 minutes when Vincent Sasso fired straight at Battinelli from an accurate pull-back from Sam Hutchinson.
But the visitors took the points on 79 minutes when Ayite delivered an accurate free kick into the mix and Kebano bundled home at the back post.
Kebano sprinted through on goal with three minutes to go only to be thwarted by a stunning save from Wildsmith, who tipped onto the bar to prevent what would have been a harsh 3-1 scoreline.
Wednesday: Wildsmith, Palmer, Sasso, Semedo, Fox, Matias (S/O 45), Hutchinson (Emanuelson 74), Lee (Buckley 61), Jones, Rhodes (Nuhiu 77), Winnall