Dominick was one of Ash's opponents during the conference. He battled Ash in From Brags to Riches. Dominick sent out his Tropius and Swalot against Ash's Torkoal and Corphish. While Corphish tried to flood Swalot with BubbleBeam, Torkoal and Tropius went at each other with Overheat and Flamethrower and Bullet Seed and SolarBeam, respectively. Tropius kept on flying while Torkoal kept using Iron Defense to shield itself. Eventually, both Pokémon ended up knocking each other out.
No matter what attack Corphish unleashed on Swalot, from its BubbleBeam to its Crabhammer, the Poison-type absorbed all of them. Swalot was also capable of fighting back with its Sludge Bomb and Shock Wave. Finally, Corphish was capable of protecting itself from the Shock Wave by using its pincers. It then used BubbleBeam inside of Swalot's mouth. Sure enough, Swalot was sent flying from all of the water inside of it. Ash was declared the victor and moved on to his next battle. Dominick was eliminated from the tournament.
[credit to bulbapedia]