It seems that rather than a true "loser's bracket", Oono was entered into a "second chance bracket" (and already finished/won that)
They're in a single-elimination tournament, but people who lost in the group stage got a second chance to enter the "real" single-elim tournament.
Edit: anyway, this chapter was hype as fuck. I think Haruo is legitimately going to win round 2, his first legitimate round victory against her ever (her broken controller didn't count lol), but I have no idea how round 3 is going to go.
@Crookshanks Oono won the Last Chance tournament basically to get back into the main tournament. Many tournaments in Japan still uses the "single game, single elimination" format with an LCQ spot or spots. The last big one that used this same format was Summer 3s 3 on 3 Mania tournament and ST XMANIA just a few weeks ago.