The espeon uses shadow ball at the pokeball and the pokeball is destroyed. You realize just throwing pokeballs isn't going to work, and you'll have to weaken or distract this espeon first.
(If you had a pokeball, you could, but this espeon is very athletic and will most like dodge or destroy the pokeball you should either attack it with your poke'mon or throw a poffin. Or throwing multiple pokeballs at a time could work)