The Premier League side face Freiburg in Istanbul on May 20 after the Bundesliga team beat Braga 4-3 on aggregate.
Trailing 1-0 from the first leg, Unai Emery’s Villa team came out all guns blazing at a pulsating Villa Park and got the lead their dominance deserved in the 36th minute when Watkins tapped in following brilliant footwork from Emiliano Buendia.
Thirteen minutes into the second half, Buendia got Villa’s second with a coolly-struck penalty after Nikola Milenkovic needlessly tugged Pau Torres’ shirt in the area.
Captain McGinn swept in carbon-copy goals in the 77th and 80th minutes to spark delirium amongst most of the 43,000 fans, including Villa-supporting Prince William.
Villa were European champions in 1982 and last won silverware when they lifted the League Cup in 1996.
They will hope four-times Europa League winner Emery can add to his tally – for the first time with an English club.
“There’s no better manager than this to get us prepared for this game and obviously take us into the final as well,” said goalscorer Watkins, whose head was bandaged for most of the game after an early clash. “His track record speaks for itself. We’re in a great position. We need to go there and win now.”
Emery’s unmatched four Europe League wins as a manager include three with Sevilla and one with Villarreal.
Buendia said the extraordinary atmosphere at Villa Park – one of the best most fans could remember – played a huge part in enabling Villa to dominate the game.
“They were a 12th man,” he said. “We’ve shown all season how well we can play, and we did it today, we deserved this.”
Apart from one early shot by Omari Hutchinson, Forest went down tamely, managing only two shots on target to Villa’s 10.
Villa’s fellow Midlands side Forest – also European champions, in 1979 and 1980 – have also been waiting a long time for a trophy since their League Cup win in 1990.
In truth, though, they were utterly outplayed on the night by a team 11 places above them in the Premier League.
“It was a great performance all round,” said two-goal McGinn. “The atmosphere in here was electric … but we’ve still got one game to go to achieve what we want to achieve.”