Wing's predatory strike just after the half-hour mark cancelled out the Royals' beautiful opener scored by teenager Danny Loader in the 11th minute.
And Middlesbrough took command by hitting what proved to be the winner six minutes before half-time when Britt Assombalonga converted a penalty to grab his 15th goal of the season.
It was a victory over Reading, who were effectively safe before kick-off, that kept the home side level on points with Derby in sixth going into a final-day trip to Rotherham next Sunday.
Middlesbrough knew that defeat would have made a play-off place even more unlikely, although missing out would not be guaranteed whatever the result had been against Reading.
In a bid to bounce back from Easter Monday's defeat at Nottingham Forest, Middlesbrough boss Tony Pulis sprung a surprise by recalling midfielder Wing to the starting line-up after hernia surgery.
It was a move that had the desired effect too, even if Boro and the club's fans were dealt an early blow when teenager Loader scored a first senior goal to remember.
After collecting Chris Gunter's throw, the 18-year-old turned John Obi Mikel before finding space and curling brilliantly into the top-left corner of Darren Randolph's net.
That led to a period of nerves in the Middlesbrough defence and the fans had just started to get anxious when things turned around, which was sparked by the performances of Wing and Jonny Howson.
Wing had already hit the post with an earlier effort and seen goalkeeper Emiliano Martinez tip over the crossbar before his persistence did find the net.
The former non-league midfielder was on hand in the 31st minute when Howson's deep right-wing cross bounced off defender Andy Yiadom.
Worse was to come for the Reading full-back because – eight minutes later – he was guilty of tripping George Saville in the area after he had brought down another Howson cross.
Assombalonga, who had the ball in the net but had it ruled out for that trip, then displayed his calmness to stay confident enough to send Martinez the wrong way from the penalty spot to give Middlesbrough the half-time lead.
Rather than build on that the home side – like many other occasions this season – went into their shell and Reading enjoyed more possession after the restart.
Randolph was not seriously tested, but there were scares like when Aden Flint had to block Garath McCleary's goal-bound effort midway through the second half.
There was another too in the dying seconds when substitute Callum Harriott's backheel needed a strong save from Randolph's legs after Yiadom's strong run and centre.