This brings back some old memories.
When I was six or seven, I played Sapphire for the first time. Me being young and all, I really only used my starter, plus a few other Pokeon. My only other team members I remembered was my Plusle, Plusy, and a Swablu I used to fly. I saved before Steven, and got owned many times over. My poor Blaziken's Blaze Kick just did not cut it. Finally, after many tries, I managed to take the champion down.
Fast forward to these remakes, I was able to beat Steven, with my Pokemon in the high fourties, on my first attempt. My Metagross really helped with taking down his Metagross, who just loved to use Giga impact on me.