Ash sends out Pikachu. Katie withdraws Golduck and sends out Dugtrio, so Ash withdraws Pikachu and sends out Swelnoofcoursehedoesn't, he keeps Pikachu out against something that can obliterate it, and Dugtrio wins easily. Fortunately, Ash's Glalie defeats Dugtrio easily.
Not that the writers were thinking about it at the time but, Dugtrio can have Arena Trap.
--
Pokemon VGC2011 NW Regional - Top 8
Pokemon VGC2011 US Nationals - 54th place