Fulham expected a tougher task than this.
But goals from Sone Aluko, Chris Martin, Ryan Sessegnon, Stefan Johansen and just a solitary Hull reply made this a tie over long before the last two goals.
Fulham bossed the game from first to last.
Marcus Bettinelli even saved two penalties in the space of a minute towards the end.
A simple back post cross headed back into the path saw Aluko volley home left-footed from eight yards to rock the Premier League club from the outset.
In fact, he almost got a second as he wriggled past two defenders only for a third to stick a foot out and deflect the effort.
Ryan Sessegnon posed a constant threat down the left and looked to have scored a second shortly before the break when he fired under Eldin Jakupovic only to see the offside flag raised.
Hull were back in it four minutes after the break when Fulham went to sleep at the back post and Goebel Evandro stooped to head home a deep cross from the left.
It lasted about as long as the Hull cheers.
Whites were ahead a second time when Aluko's pass beyond the final defender allowed the teenager to put in Martin for an open goal.
Martin returned the favour on 66 minutes as Hull looked a beaten bunch even before then. This time, Sessegnon needed to fire past the keeper, but that he did for 3-1.
Johansen notched the fourth from a brilliant Tom Cairney move, and then Bettinelli performed heroics to dive left and stop Abel Hernandez's 12-yarder after a foul by Tomas Kalas, and then again when the keeper upended the taker.
Great stuff, and another Sunday win.
Of course Sone Aluko scored - he had to
It is an unwritten rule that a player facing his old side scores or is totally anonymous.
Fortunately for Fulham, it was the former as he caused all sorts of problems with mazy runs as well a devastating pass to set up Fulham's second.
Ryan Sessegnon - and his mixed bag
Going forward the 16-year-old is a handful. Going back he has a lot to learn,
He was nowhere when Hull scored the leveller, but his astute run to provide Martin's tap-in was top drawer. And his goal as he ran into the right channel sums up where the talent is right now.
Marcus Bettinelli versus David Button for the gloves
The former had nothing to do for 85 minutes and then the keeper saved two penalties, and just for a bit of icing on top, tipped a fierce drive from sub Josh Tymon around the post.
How well did Fulham play today?
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