Ott Tänak's Vodafone Rally de Portugal lead was hanging by a thread on Saturday night after a dramatic finale to the penultimate leg.
He clung onto a 4.3sec lead over Toyota Gazoo Racing colleague Kris Meeke after damage to his Yaris' front right suspension left him limping through the final speed test – the longest of the rally at almost 40km.
An identical problem for team-mate Jari-Matti Latvala, on the other side of the car, sidelined the Finn from second place before the same test after he was on course to deny Tänak a second consecutive WRC victory.
Brake problems in the opening test slowed Tänak and two stage wins for Latvala slashed the Estonian’s overnight lead from 17.3sec to 5.1sec.
Latvala damaged his suspension after a heavy landing in the afternoon’s opener. He struggled through the next test before stopping, leaving Tänak 15.2sec clear of Meeke before the leader struck trouble of his own.
“Twenty-five kilometres before the finish we broke the front right damper. Five kilometres after I went wide in a corner and had to reverse. It was a challenging stage. Tomorrow, if there are no issues, it should be a good day,” said Tänak.
The top three places were blanketed by 9.2sec as Thierry Neuville won the final two stages in a Hyundai i20 to close to within 4.9sec of Meeke.
A hydraulic problem meant Meeke could not use his handbrake in the last stage, which was littered with hairpin bends. The Briton limited the time loss to stay ahead of Neuville and set up a pulsating battle for the podium on Sunday.
High temperatures, hanging dust and rough roads ensured the leg, which comprised more than half the rally’s competitive distance, was a gruelling challenge.
Championship leader Sébastien Ogier was fourth in a Citroen C3, 21.0sec off the lead and an unwitting player in a double dose of tactics by Neuville's Hyundai team.
With Dani Sordo and Sébastien Loeb out of the running for a top place after fuel pressure problems on Friday, the Korean squad ordered them to deliberately incur time penalties by dropping down the start order to slot in after Ogier and ahead of Neuville.
It meant Ogier had two cars fewer starting before him to sweep loose gravel from the road and provide a cleaner and faster line.
Team-mate Esapekka Lappi climbed from eighth to fifth, leap-frogging Teemu Suninen, who was almost half a minute behind in a Ford Fiesta.
Sunday's finale is the shortest of the weekend. Five sandy stages include a double run over the famous Fafe test, the second of which forms the Wolf Power Stage with bonus points for the fastest five crews. They add up to 51.77km.
Leading positions after Saturday:
1. O Tänak / M Järveoja EST Toyota Yaris 2hr 47min 23.1sec
2. K Meeke / S Marshall GBR Toyota Yaris +4.3sec
3. T Neuville / N Gilsoul BEL Hyundai i20 +9.2sec
4. S Ogier / J Ingrassia FRA Citroën C3 +21.0sec
5. E Lappi / J Ferm FIN Citroën C3 +1min 37.5sec
6. T Suninen / M Salminen FIN Ford Fiesta +2min 02.7sec