Promotion-chasing Reading made it six successive wins as substitute Adam Le Fondre's second-half goal gave them victory at Millwall.
The Royals were trailing at the Den after Harry Kane lofted a pass over the defence for Andy Keogh to finish.
But in first-half stoppage time Hal Robson-Kanu volleyed the Royals level from a corner.
Le Fondre completed the comeback when he tucked in Jason Roberts' cross at the far post.
The win continues Reading's charge up the Championship table and leaves them just a point behind second-placed West Ham, having played a game more.
However, despite their recent form, Brian McDermott's men were out of sorts for much of the first half.
They were punished by Keogh's 15th minute goal - the first the Royals have conceded in 490 minutes and only Millwall's second at home in the league this year.
However, late in the half they were given a lifeline as home keeper David Forde's punch from a corner fell to Robson-Kanu and he thumped a superb volley high into the net.
Millwall could have regained the lead but Kane missed James Henry's cross with the goal gaping.
The Lions paid for the miss with 15 minutes to go when Roberts broke the offside trap and laid the ball into the path of Le Fondre who made no mistake at the back post.
Millwall manager Kenny Jackett: "You have to grind results out, we had a deserved lead and matched an in-form Reading side.
"But ultimately it's two poor goals against us and that's been the difference. We haven't seen it through and been professional enough.
"We've tried everything to turn this home form around and it's only us who can get ourselves out of it. Too many times games like today have slipped through our fingers."
Reading manager Brian McDermott: "The pitch was difficult and to go one down here is not easy.
"We are on a great run and we are really pleased. We are trying to win every game, that's all we're concentrating on.
"The players have fantastic guts, they know how to win games, they know what's required and there's a really good camaraderie between everyone."