The decisive engagement of the war came when Lysimachus invaded and overran much of western Anatolia, but was soon isolated by <answer>Antigonus</answer> and Demetrius near Ipsus in Phrygia. Seleucus arrived in time to save Lysimachus and utterly crushed <answer>Antigonus</answer> at the Battle of Ipsus in 301 BCE. Seleucus' war elephants proved decisive, <answer>Antigonus</answer> was killed, and Demetrius fled back to Greece to attempt to preserve the remnants of his rule there by recapturing a rebellious Athens. Meanwhile, Lysimachus took over Ionia, Seleucus took Cilicia, and Ptolemy captured Cyprus.
Who lost in the Battle of Ipsus?
Antigonus