O'Neill praise for Fletcher
The Scotland international was not even expected to be involved on Tuesday night as he continued his recovery from an ankle injury but declared himself fit on Tuesday morning to hand his manager and team-mates a boost.
He then capped an impressive display with the second of three unanswered goals to help the Black Cats climb out of the Barclays Premier League relegation zone. And O'Neill said: "Fletcher had done absolutely no work whatsoever. When you were talking to me (before the game), I genuinely wasn't sure that he could play in the game."
O'Neill added: "He came out just to do a bit of a loosener and thought he wanted to give it a go. I personally thought if he could see it to half-time and just slightly into the second half, he would do great for us.
"He has been terrific for us, really terrific. You just feel that he is likely to get you a goal in there. Danny Rose did very, very well, but when it came in, he turned it into a goal for us and it was great."
If it was Fletcher's 28th-minute strike, his seventh of the season which came courtesy of an audacious back-heel from Rose's low cross, which gave Sunderland breathing space, it was James McClean's third-minute opener which lifted the tension hanging over the Stadium of Light.
Reading, who have won only one league game since their promotion from the npower Championship, never looked like getting back into it, although it was not until injury time that Stephane Sessegnon ran on to Carlos Cuellar's long ball and rounded Adam Federici to cement just a third league win in 24 attempts.
But while there was relief for O'Neill, opposite number Brian McDermott headed away from Wearside knowing he is in the thick of a survival battle.
He said: "Do I fear for my future? I don't have fear about it. I have been in football for 30-odd years now and I know this club is in a far healthier position than it was a year ago, two years ago, when we were staring League One in the face three years ago.
"Where we are now as a club, we are in a far healthier position, so that's the most important thing for me, the club. I am just disappointed with the results. I have been used to winning games over a long period of time and we are not winning games."