Championship leader Rovanpera started the day third, 25.5s down on overnight leader Neuville, but returned to the service park with a 2m04.4s rally lead over Hyundai’s Dani Sordo.
Hyundai's Neuville retired from the lead on the afternoon’s first stage, handing the advantage to Ogier. However, the Toyota driver then lost four minutes to a suspension issue on the afternoon’s last test, dropping the Frenchman to fourth overall.
As a result of the late drama, Toyota’s Elfyn Evans ended the day third (+2m09.4s) despite dropping more than a minute to an overheating issues on his GR Yaris in the final stage of the morning loop.
Behind Ogier, M-Sport’s Ott Tanak moved up to fifth (+4m49.7s), the Estonian hampered by a 3m40s penalty on Friday after repairs to a water pump issue meant he was late leaving a tyre fitting zone.
Hyundai’s Esapekka Lappi brought his wounded i20 N through the day’s final stage in sixth ahead of Toyota’s Takamoto Katsuta, who suffered pair of punctures during the afternoon.
The afternoon loop started in dramatic fashion as Neuville’s hopes of repeating last year’s Acropolis victory vanished on stage 10 (Pavliani, 24.25km).
The Belgian struck a hole in the road 11 kilometres in, which bent his front right wheel and damaged the suspension beyond a roadside repair.
Neuville’s demise handed the lead to Ogier, who completed the stage with the second fastest time behind pacesetter Rovanpera.
Driving on roads that were much drier compared to the first pass but even rougher, Rovanpera edged Ogier by 0.2s and reduced the gap to the new rally leader to 12.6s.
Sordo inherited third (+1m48.2s) but was just 1.6s ahead of Evans after the Welshman's suspected overheating issue was remedied during the midday service, allowing him to post the third fastest time on stage 10.
Greece’s rough gravel roads continued to bite in stage 11 (Karoutes), as Lappi and Katsuta were both delayed by problems.
Katsuta dropped 4m35.7s after stopping twice to change punctured front left and right tyres. The delay was enough to allow Lappi to pass the Japanese driver in the stage, although the Finn’s car wasn’t in rude health thanks to an alternator failure and a transmission issue.
These brought Tanak back into the fight, moving to fifth ahead of Katsuta and Lappi.
At the front, the battle for the victory raged on with Rovanpera again pipping Ogier by 0.2s to win the stage, closing to within 12.4s.
There was more positive news for Toyota as the recovering Evans leapfrogged Sordo by 4.1s to create a 1-2-3 in the overall standings for the Japanese brand. The position change came despite Evans suffering a tyre off the rim towards the end of the stage.
But the final stage of the loop (Eleftherochori, 18.02km) offered yet another twist as Ogier became the latest driver to pick up a mechanical problem on the abrasive roads.
The eight-time world champion suffered a left rear suspension failure and a puncture, costing him the lead and four minutes in the process.
Ogier limped to the stage end and was seen working on his car to allow him to make the 27 kilometres drive to the Lamia service park.
Team-mate and new rally leader Rovanpera took the stage win by 12.9s from Sordo.
“It was a nice battle, of course not the easiest to push with Seb because we had the championship to push for,” said Rovanpera. “I think we had a good day, we were fast but we also kept the car in one piece.”
In WRC2, Andreas Mikkelsen will head into Sunday's stages with a slender 0.4s lead over Gus Greensmith.
The rally will conclude following Sunday’s three stages.
