Vetokele, the Addicks’ top scorer this season, entered the fray to a hero’s reception just after the hour mark with the game seemingly slipping away from his team’s grasp.
But the Belgian popped up just five minutes after his introduction to tap home his seventh goal of the season from Rhoys Wiggins’ cross and extend Charlton’s unbeaten run at The Valley to eight games.
Until then it had been the Royston Drenthe show, with the forward flitting effortlessly across the Owls’ front three and capping a thrilling first-half display with a stunning goal to put Wednesday in the driving seat at the break.
But Charlton rallied in the second half to earn a share of the spoils and keep them in touch with the Championship’s top six.
Former Real Madrid winger Drenthe was a cut above the rest in the opening 45 minutes of his first Wednesday start, whipping a teasing centre just beyond Atdhe Nuhiu before fizzing a left-footed shot just past Stephen Henderson’s post from 20 yards.
And having found his range, it was the Dutchman who sent the 2,000 travelling fans into raptures on 27 minutes. After neatly spinning past Franck Moussa on the half-way line, Drenthe ran at the Charlton back four – and they had no answer to his sheer pace and power.
He ghosted inside left-back Wiggins far too easily before drilling a crisp shot from the edge of the D past the helpless Henderson and into the bottom right-hand corner to register his first goal since signing on loan from Reading.
Having seen Wednesday’s wing wizard tear his side apart during the first half, Charlton boss Bob Peeters turned to wideman Johann Gudmundsson at the interval as his side displayed a renewed vigour after the break.
Chris Solly’s 30-yard thunderbolt almost got them back on level terms, before George Tucudean’s mis-hit volley cannoned into the ground and clipped the top of the cross bar on its way over as the Addicks began to turn the screw.
On 70 minutes, that pressure finally paid off. Wiggins, who was at fault for the first goal, picked the ball up inside his own half and surged forward from left-back, jinking inside Liam Palmer who was scared to make a challenge just inside his own penalty area.
The defender’s cross-cum-shot flew across the box for substitute Vetokele, who found himself in the right place at the right time to tap home from six yards.
The Addicks thought they had found a late winner in the first minute of stoppage time, but Gudmundsson’s strike was correctly ruled out for offside as both sides were left to settle for a point.