Danny Williams' 11th-minute goal also inflicted Paul Lambert's first defeat as Rovers boss
McDermott returned to Reading this week, replacing Steve Clarke, after leaving in 2013 to lift the Royals up to 11th in the Sky Bet Championship
Williams' stunning half-volley won it in the first half and Reading held out to end a four-game losing streak
Sheffield Wednesday closed in on the Sky Bet Championship play-offs after a 4-1 demolition of Wolves
The Owls came from behind and now sit just a point behind the top six as they recorded a first home win over the visitors since 1964
Daniel Pudil and Gary Hooper completed the rout after Benik Afobe's penalty had given Wolves the lead at Hillsborough
Afobe's 16th-minute goal, after Ross Wallace had fouled Matt Doherty, had Wolves dreaming of just their third win in 12 games but Forestieri netted a spot kick of his own four minutes later when Lucas Joao went down inside the box
Wednesday took the lead when Forestieri's deflected 20th-minute effort flew past Carl Ikeme and Pudil made it 3-1 with his second goal of the season after the break
Norwich loanee Hooper then finished the visitors, who remain 17th, off in stoppage time when he latched onto Atdhe Nuhiu pass
Elsewhere, Alan Browne's own goal gave Leeds a 1-0 victory over 10-man Preston
North End keeper Jordan Pickford was dismissed for handling outside the box after just half an hour and then Browne headed Stuart Dallas' cross into his own net just 30 seconds after the break
Source : PA
Source: PA