Ott Tanak built on his overnight lead by taking five of Saturday's six stages in the Acropolis Rally.
Tanak started the day just three seconds ahead of Hyundai team-mate Adrien Fourmaux and finished it 43.6 seconds ahead of Toyota's French driver Sebastien Ogier.
Frenchman Fourmaux dropped to third, at 1min 24.4sec, after hitting a rock in the final stage.
Championship leader Elfyn Evans was fourth overall, more than three minutes behind Tanak.
The gravel roads took their toll down the field. Both Finn Kalle Rovanpera, the 2022 and 2023 world champion, and his Toyota teammate Takamoto Katsuta crashed out on the fourth stage of the day.
"It's Greece," said Tanak. "You need your eyes wide open all the time. You never know what's coming."
The rally concludes on Sunday with four more stages, at the end of which Tanak could secure Hyundai its first victory of the season.