The Battle of Naupactus, which took place a week after the Athenian victory at Rhium, set an Athenian fleet of twenty ships, commanded by Phormio, against a Peloponnesian fleet of seventy-seven ships, commanded by Cnemus. The Athenian victory at Naupactus put an end to Sparta's attempt to challenge Athens in the Corinthian gulf and the Northwest, and secured Athens' dominance at sea. At Naupactus, the Athenians' backs had been against the wall; a defeat there would have lost Athens its foothold in the Corinthian gulf and encouraged the Peloponnesians to attempt further aggressive operations at sea.