Sasuke didn't lose...he took them all on, practically at once and survived
In his fight with Ay, he was just learning to partially summon Susano'o and even with just a rib cage summon he was holding off Ay and winning actually because Ay was set to be engulfed by Amaterasu had he continued with his leg chop that Gaara saved him from and allowed Ay to take a time out while Gaara distracted Sasuke to allow Ay to sever his arm to keep the Amaterasu on it from spreading
Gaara would have also got own. Sasuke owned Gaara in PartI; the only thing that saved Gaara when they fought during the chuunin exams was transforming into Shikaku mode....with Shikaku ripped from him Gaara no longer has the one thing that saved him from Sasuke
Sasuke killed Danzo
and his brief clash with Mei & Onoki ended in a stale mate as neither of their most powerful attacks were about to touch an exhausted Sasuke who just got done handling Ay
And now that Sasuke has practically perfected his Susano'o the 5 Gokages each don't stand a chance
