Holloway said: "I wrote the word ugly on the board at half-time and I wasn't talking about myself, although I could have been.
"It was a very difficult game for both sides but we did the right things. Reading won four games in a row so that is a major scalp for us.
"We put our bodies in the right places and scored two magnificent goals which won us the game."
The goals came either side of half time and Scottish international midfielder Adam had a major hand in both.
Adam created the first with a pinpoint pass for Campbell who deftly flipped his shot over the advancing Reading keeper Adam Federici.
Holloway revealed that Adam had been complaining of an injury at half-time but he certainly looked fit enough as he fired home his 13th goal of the season in the 73rd minute.
It was a rare right-footed effort for Adam and Holloway said: "If he can score goals like that with his right foot we don't need to worry about his left."
And Holloway said his side would continue to fight for a play-off spot.
"We dropped nine points in three games so we're playing catch-up but there's a lot of the season left to go and an awful lot of points still to fight for."
Reading boss Brian McDermott said: "The pitch makes it a bit of a lottery but having said that they played the pitch better than we did although I know Ian doesn't want to play on a pitch like that any more than we do.
"We were flat today. We didn't do enough and I don't know why that is.
"We have come off a really good run and what's happened today doesn't make us a bad team, just as the first great wins didn't make us into world beaters."
Reading, like their hosts, were forced to use all three substitutes and were particularly hard hit by the loss of the influential Brynjar Gunnarsson who was replaced after just half an hour.
But McDermott refused to blame the crowded fixture list for his problems and said he was looking forward to the mid-week FA Cup replay against West Brom.
He added: "The cup run had galvanised the club and put us back on the map which is important."