I mean seriously HOW?!
-Awakened the power of his body after harsh training ( according to Hagoromo ) :
-Was apparently a Jinchuriki or at least a Pseudo Jinchuriki ( like Naruto with the 1 tail through 8 tail Bijuu )
-Got the Six Path Yang Power and Six Path Yin Power from Hagoromo ( In other words he got both Naruto and Sasuke's Power up )
While Indra didn't even have the Rinnegan because between Hagoromo and Sasuke , only Madara awakened it :
Forget about stalemating , how did Indra even stood up to Asura ?!