Newer DM, looking for advice on presenting the results of a battle to my players.

My players have completed a series of challenges in an underground dungeon (an old converted silver mine). Their party will be ranked amongst 5 other parties, based upon their speed and how many tokens they recovered within the dungeon.

The next step is a tournament, the top two parties get a bye. Parties ranked 3 and 6 will battle, and parties ranked 4 and 5 will battle. Tournament-style, and with only a long rest in-between each battle.

My question is how would you present the other parties battles to the players’ party? I want to make the battles occur within an arena-type situation, with crowds of fans and onlookers. Would you just narrate straight up a battle, or would you try to come up with some sort of dice-rolling scenario?

All suggestions are welcome!