Brian McDermott's side go on a run of 15 wins from their last 17 games which sees the Royals secure a return to the top flight after a four-year absence
Their win over Forest and West Ham's draw at Bristol City sees the Berkshire club return to the top flight after a four-year absence, with relegation in 2008 suffered on the back of two seasons in the Premier League.
The Royals have won 15 of their last 17 league games since losing to Hull City in January to storm from eighth in the table to the very top.
Brian McDermott's side can secure the league title with four points from their remaining two fixtures, while second-placed Southampton need two points from two games to secure promotion.
"I'm delighted and it's a great night for us," McDermott told BBC Radio 5 Live after the game. "It was a tough game tonight. I couldn't see too much good in losing that play-off final at Wembley final last year, but perhaps this is meant to be.
"I'm not even bothered about the Premier League tonight, I'm just concerned about the players and staff. It's a night for the fans."
Reading were beaten finalists in the play-offs last season as Swansea City were promoted to the Premier League for the first time, and McDermott, who has been with the club for 11 years in total, took over from current Swans boss Brendan Rodgers as manager in 2009.
Key to the Royals' success has been 11 goals in 29 appearances from former Rotherham striker Adam Le Fondre, and six in 15 appearances scored by Jason Roberts, a signing from struggling Blackburn Rovers.
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