Feigned retreat
At the Battle of Salamis in 480 BC, the Ancient Greeks were fighting a sea battle with the more numerous Persian navy. Themistocles, the Greek leader, leaked information that was taken back to the Persians that the Greeks were ready to flee and that if the Persians acted right away, they could claim a huge victory. While not an actual feigned retreat but more a rumored one, it worked just as well, as the Persians were defeated.