Leeds took first blood in the two cup final showdowns by lifting the Harold Feldman Trophy.
A 3-1 win ended the MJSJL winner's treble bid as goals from Louie Hewson (2) an Jon Zolte proved enough for the Yorkshireman.
But boss Kristall immediately turned his attention to Sunday's rematch in the Shonn Trophy.
Kristall told JC Sport: "They will be hurting and will be a wounded animal. We expect them to come out with a point to prove. So it's important we put this to the back of our minds and concentrate on repeating he same result.
"We will keep the same mindset and show the champions the respect they deserve."
Haroldeans had been the dominant force this step but Leeds found an extra spring in their step to stun Mike Bloomberg's men.
Hewson struck twice, his second with an overhead kick, with Zolte's bullet header ending the contest. Bobby Fishel hit back but it was no more than a consolation.
Kristall commented: "We went in to the game very much as underdogs as Haroldeans not only had the treble in their sights but they also have the league's top goal-scorer in Adam Shiffman.
"The message to the players was stay in the game early doors and give ourselves a platform to build on.
"To come through was fantastic. It was a great team display and it was impossible to pick out one player as everyone, including the substitutes, played their part."
Bloomberg is already plotting a revenge mission, adding: "We have no complaints as the better team won. Leeds were very well organised, strong at both ends of the pitch and wanted it more than us.
"We all need to look at ourselves, myself included. I expect a reaction on Sunday."
Meanwhile Mark Mann had the honour of lifting the Tony Cohen Cup for Maccabi Manchester Blue.
A 3-1 win over Prestfield saw the Blues cruise home.
Charlie Simpson, Nathan Pitt and Max Rose were all on target. Jonny Franks grabbed a consolation for Prestfield, who were well beaten.
