After winning, follow the prize objective and speak to Sir Hanush. A win earns 400 groschen, and the first five tournament victories award the five pieces of the Lords of Leipa armor set. One win gets you one piece, so collecting the full set means returning for more tournaments. Later victories continue to provide equipment rewards.
Now for the part I'd prepare for before that first victory: carry an Antidote and keep your normal combat equipment ready. Black Peter can ambush Henry near Rattay Mill after losing to him. Watch the path by Peshek's place for a rope stretched across it. Riding straight into that can knock you off your horse and put you into the fight on his terms.
His sword is poisoned. Winning the fight doesn't automatically remove the poison if he managed to cut you, so check Henry's condition immediately afterward. Use the Antidote when you're able to consume it, and deal with bleeding separately if needed. Don't assume a nearly full health bar means you can ignore the poison and ride off to sell your loot.
After winning, follow the prize objective and speak to Sir Hanush. A win earns 400 groschen, and the first five tournament victories award the five pieces of the Lords of Leipa…
· Games / Kingdom Come: Deliverance