According to Galatians 2:11, whom did Paul oppose to his face at Antioch?

Answer: Cephas (Peter)

Cephas (KJV: Peter) had eaten with Gentiles but drew back for fear of the circumcision group; Paul opposed him to his face.

“When Cephas came to Antioch, however, I opposed him to his face, because he stood condemned.”— Galatians 2:11 (BSB)