I think that was actually Dragon Rage that Charizard was using, as we see him use it several times after that; most notably in his match against Drake's Dragonite: almost the exact same sequence.
This is one of my favorite episodes in the Orange League season. Char finally obeys Ash for good, leading to a pretty awesome battle(w/Pokémon World in the BG!). I liked Poliwrath's makeshift WWF() title belt--notice it had a hole for it to shoot its Water Gun and Hydro Pump.
Easy 10/10. What more can you ask for in a Charizard featured episode?