Panathinaikos close in on leaders Olympiakos
Olympiakos allowed Panathinaikos to close the gap after they were held to a goalless draw at struggling Doxa Dramas.
Leto returned to the starting line-up after injury and netted the only goal of the game after 24 minutes to take his tally to the season to 15 goals.
"I am happy with the result but not with the performance, and the only way we can change that is through hard work on the training pitch," said Panathinaikos coach Jesualdo Ferreira.
Ferreira's men have collected 33 points from 14 games and are closing in on Olympiakos as they have two games in hand.
The champions were below-par but came close to clinching the three points when striker Rafik Djebbour hit the post with a header on the hour mark with Doxa goalkeeper Dino Seremet also making a superb reflex save to deny Avraam Papadopoulos from the rebound.
It is the second match in succession that basement club Doxa have produced a surprise result following their scoreless draw with AEK Athens at the Olympic Stadium in midweek.