With four stages remaining today, Neuville’s advantage is up to 16.2sec.
"I am not really sure if Ott has problems - I think if Ott has problems then I have only three cylinders!” Neuville joked.
“Of course, we want to fight for the victory and I had to give it a go. We are getting a bit better with the car, but I feel like there is some more [speed] to come - we just need to find it."
Tänak was unable to elaborate too much on his issue, but he did explain it was something related to the car’s four-wheel drive system.
Just 2.5 split the Korean manufacturer pairing after Friday’s opening leg and Tänak - fresh from victory in Finland last time out - wasted no time in pressuring the overnight leader.
He was fastest out of the blocks and outpaced a sleepy Neuville by 2.6sec in the opening Reninge blast to move ahead by just one-tenth of a second.
The next stage at Dikkebus had to be halted when Craig Breen, driving an M-Sport Ford Puma, ran wide into a ditch on the outside of a left-hand corner and rolled into retirement while running fifth overall.
By the time action resumed on SS11, Neuville was back into his groove. Unfazed by some nervous handling from his i20, the Belgian outpaced his team-mate by 6.2sec to snatch back the top spot before adding another huge 9.9sec to his arsenal in the final test as Tänak complained of transmission issues.
"It's affecting us a lot," he said. "I came through as smooth as I could but we have very inconsistent four-wheel drive at the moment and it's so disappointing. You can drive it, but not like a rally car."
Elfyn Evans closed in on Tänak and ended just 5.3sec behind to complete the top-three. He had a hefty 37.2sec in hand over Toyota GR Yaris partner Esapekka Lappi, who was all smiles after a neat and tidy loop.
Adrien Fourmaux was more than two minutes back from the leaders but gained a position when Puma colleague Breen rolled out of contention. The Frenchman also leapfrogged Oliver Solberg and held fifth overall, just 4.5sec in front of his Hyundai rival.
Takamoto Katsuta climbed from 18th to seventh overall despite running into hybrid boost issues on his Yaris, while WRC2 frontrunners Stéphane Lefebvre, Andreas Mikkelsen and Yohan Rossel completed the top 10.
Gus Greensmith slid wide into a ditch on Dikkebus and, although the M-Sport driver was able to continue, he dropped over 10 minutes during the loop while nursing damaged rear suspension.
- Full coverage from Renties Ypres Rally Belgium is available on WRC+ All Live here, including every stage broadcast as it happens as well as key interviews, features and expert analysis from the service park.
Finland
Italy
Hungary