Wigan completed a league double over the Royals with a convincing 3-0 victory that flattered the visitors immensely.
And Adkins believes Uwe Rosler's side will be a tough nut to crack in the end-of-season play-offs.
"Wigan are the best team we've played this season," said Adkins. "They gave us more problems than anyone we've played.
"From my point of view, the level of our performance was nowhere near the level that we needed to be or expect.
"The three goals we conceded, we didn't stay with our runners, and we haven't dealt with situations as we should have.
"Wigan got the flow of the game in the first half, and they deservedly got control of the game. We came out in the second half determined to do better, but the third goal is a shocking goal to give away, which made it even more challenging."
Reading have now dropped out of the top six with rivals Brighton picking up a point at Huddersfield but Adkins insists all is still to play for heading into the last three matches.
"We're still in there, we're in the mix, we're in the race," he added.
"There's three games to go, and it's all to play for. We just need to make sure we're bang at it for the last three games.
"We need three wins, that's what we have to go and do. We'll reflect on this day and make sure that the 11 men who run out for the next game are willing to run through a brick wall.
"Obviously every game has its own importance, but what we have to do now is get ourselves up for the next one.
"We've been on a very good away run of form this season, but that level slipped today. Was that down to us or was it down to how well Wigan played?
"We never got near a very good, mobile Wigan midfield today, and we couldn't get hold of the football. And whoever has the football obviously a better chance of going on to win the game."
Latics boss Rosler showed a touch of class by kicking off his press conference with a message of congratulations to newly-promoted Brentford, the League One side he left to join Wigan just before Christmas.
"Before I start I would like to congratulate my former club," he said. "I'm very happy for the players, the staff, the supporters - everybody connected to Brentford.
"I know how hard everyone has been working - both while I was there and since I have left - and it's a fantastic achievement."
There is now a six-point gap in the Championship table between Wigan and seventh-placed Reading, with Rosler's side also having a game in hand.
And the German was left to reflect on a good day all round.
"The first 40 minutes here was to perfection," he added. "We played so much as a unit, we circulated the ball very quickly and we were helped by a very good playing surface - compliments to the ground staff for allowing us to play the way we wanted.
"The goals came at the right time, sometimes you have to shoot from outside the box against teams that defend very deep, and we should do that even more often."