Rivers was behind schedule because he was watching Tiger Woods win the Memorial Tournament for the fifth time.
“It was unbelievable,” Rivers said ahead of the game, when asked by a Boston Herald reporter.
“Oh, yeah, I was watching. I was trying to leave my house to get here (Boston’s TD Garden), and it delayed me for a couple of minutes, but that’s fine. That’s really cool.”
Rivers’ Celtics won the game in overtime, 93-91, to tie the series at two games each.