Slavisa Jokanovic's side - beaten play-off semi-finalists last season - will play either Aston Villa or Middlesbrough in the final on Saturday, 26 May.
It won't be easy, and we could envisage them needing to grind out a nervy draw and rely on some more penalty box defending late on, as they did in the first leg, if they're to get it done.
English wingback Sessegnon, 17 - whose performances have attracted the attention of Manchester United, Tottenham Hotspur and French champions Paris Saint-Germain - brought the tie level two minutes into the second-half with his 16th goal of the season, before his corner was headed home by centre-back Denis Odoi in the 66th minute.
Indeed, he netted against Derby in Fulham's 2-1 win at the iPro Stadium back in March and was an integral part of his side's 23-match unbeaten run that ended on the final day of the season.
The Rams struggled to create opportunities on the night but they were comfortable in the first-half as they dealt with consistent Fulham attacks.
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Fulham will be making it to Wembley for the first time in 43 years, where the face the victor of the game between Aston Villa and Middlesborough.
"We just need everyone behind us", Bettinelli said.
Fulham ended their play-off hoodoo in style by coming from behind to beat Derby 2-0 and put themselves one win away from the Premier League.
"I said to the players that we showed a lot of character to get into the play-offs in the first place".
Derby boss Gary Rowett felt his team had been too nervous. It's a second leg and they've more than deserved to go through.
"Fair play to Derby, they defended extremely well, but I think everyone could see we were by far the better team".