Yann Kermorgant's penalty just after half time was enough to beat Fulham 1-0 and book the Royals a place in the Championship play-off final.
Reading welcomed Fulham to the Madejski Stadium after a 1-1 draw at Craven Cottage last week.
Following a goalless first half, Martin Atkinson was forced to point to the spot after Chelsea loanee Tomas Kalas was deemed to have illegally handled the ball in the box.
Kermorgant stepped up and converted from 12 yards to as the hosts held on to one-goal advantage despite some heart-stopping moments and a terrific display from Ali Al-Habsi in the Reading goal.