The day after GFH Capital confirmed their 100% buyout of the Whites, Becchio scored either side of the break to cancel out Lucas Jutkiewicz's opener and earn his side a fifth win in six npower Championship games.
The 28-year-old took his tally for the season to 17 in the process - just three short of his best-ever return for the club - and improved his record against Boro to five in four games.
The former Barcelona B man still has 18 months to run on his contract at Elland Road but it is likely that manager Neil Warnock will be knocking on the door of his new bosses soon to try and arrange an extension as he looks to kickstart a promotion push in the new year.
In this form that looks likely for Leeds, although they still have a number of teams above them, including a Boro side who saw Scott McDonald and Jutkiewicz pass up glorious chances before the latter broke the deadlock after half an hour.
El-Hadji Diouf's lay-off was missed by all of his team-mates and allowed the visitors to pick up the ball, with Jutkiewicz racing through on Paddy Kenny's goal and drilling in a low strike which the keeper did well to save with his feet. Leeds were slow to the rebound, however, and Jutkiewicz picked it up and beat Kenny at his near post via a deflection off Alan Tate.
Leeds responded well to the goal and would have been level had Jerome Thomas squared to Diouf and not shot across goal, but the equaliser did come on the stroke of half-time, with Becchio half-volleying in via the angle of post and bar after Jonathan Woodgate failed to clean up Byram's cross.
Jutkiewicz was twice foiled by Kenny after half-time and he was forced to rue those misses with 17 minutes left.
After Becchio's header from a Diouf cross was tipped over by Steele, he rose the highest from the resulting corner to beat the goalkeeper with another nod of his head, this one taking a deflection off former United defender Woodgate.