Another player linked with a move away from the club, Cairney scored the all-important goal to send Fulham back into the Premier League, leading by example.
The Villa Park outfit managed to shut out Middlesbrough in the previous round, and will be hoping they can keep Fulham at bay for 90 minutes.
Losing key talents should no longer be a worry for Fulham after a well-deserved return to England's top flight for the first time since 2014. In the second half, we were much better.
The final year of parachute payments would see Villa have to cut their cloth accordingly and it would likely lead to the break up of Steve Bruce's squad. Whilst the likes of John Terry and Jack Grealish would nearly certainly exit as well.
There was no doubting who Villa's dangerman was and Grealish showed his class again with a brilliant mazy run on the hour mark that ended with a fine save from Bettinelli.
Fulham finished third, missing out on automatic promotion by two points.
Cairney struck with a cool finish in the first half at Wembley to earn Fulham a top-flight place worth an estimated £160 million ($213 million) windfall. "I'm happy with what my team offered today and how we played our football".
Grabban managed just one shot on goal at Wembley, with it being blocked nearly as soon as it left his foot.
"I've been playing the whole season not fully fit. I'm sure he will give it a good go if we get promoted and enjoy the challenge of it". "I'll need the summer to rest and get fit".
Villa's last Wembley appearance was 2015, when they lost 4-0 to Arsenal in the FA Cup final, but several players - among them keeper Sam Johnstone, Elmohamady and midfielder Robert Snodgrass - have previously tasted success in play-off finals.