Leon - World champion Sebastien Loeb was on course for his sixth-straight Rally Mexico victory, finishing day two on Saturday with a 36.2 second lead over Citroen team-mate Mikko Hirvonen.
The French driver extended his lead throughout the day's stages, conducted in blistering temperatures that didn't deter thousands of fans.
He won the nearly 42km 14th stage in which Hirvonen settled for third behind Jari-Matti Latvala, more than nine seconds off the lead.
Four stages remain on Sunday, one of them the 54.3km Guanajuatito stage that Loeb cautioned could still prove decisive.
"Now we have a good and comfortable situation but there is still a long way to go and a 54km stage - so still nothing is done," said Loeb, an eight-time world champion.
"It’s a rally where I have had a lot of success and I hope that continues tomorrow."
Behind second-placed Hirvonen, Latvala was in third place for the factory Ford team.
His hopes of catching the Citroens faded with a puncture on the 15th stage. He rebounded with a series of quick stages to keep a podium place within reach.
"It’s really good to see our car is very competitive," Latvala said. "Without the problems we’ve had, things could be really good."
Latvala's Ford teammate Petter Solberg overcame brake problems on Saturday morning to move ahead of fellow Norwegian Mads Ostberg. He was fourth at the end of the day with Ostberg fifth and Estonian Ott Tanak impressing in sixth position.
Tanak was hindered by a spin and a stall on stage 14 and a puncture on stage 15. His M-Sport team-mate Evgeny Novikov of Russia was forced out of the race when he ripped a wheel off his Fiesta on the final stage. That moved Qatar's Nasser Al-Attiyah up to seventh overall.
Australian Chris Atkinson was in eighth place when a loss of brakes led to a crash. He was expected to restart under Rally 2 rules on Sunday.
Rally of Mexico results on Saturday:
1. Sebastien Loeb (FRA/Citroen DS3) 3 hours 25 minutes 17 seconds
2. Mikko Hirvonen (FIN/Citroen DS3) at 36.2 secs
3. Jari-Matti Latvala (FIN/Ford Fiesta RS) 1:53.0
4. Petter Solberg (NOR/Ford Fiesta RS) 2:10.9
5. Mads Ostberg (NOR/Ford Fiesta RS) 2:44.2
6. Ott Tanak (EST/Ford Fiesta RS) 4:22.1
7. Nasser Al-Attiyah (QAT/Citroen DS3) 6:00.8
8. Armindo Araujo (POR/Mini) 10:42.1
9. Sebastien Ogier (FRA/Skoda Fabia 2000) 12:02.7
10. Ken Block (USA/Ford Fiesta) 13:51.8
Stage winners: P. Solberg 1 (SS1), Hirvonen 1 (SS2), Latvala 8 (SS3, SS6, SS7, SS8, SS13, SS16, SS17, SS20), Loeb 6 (SS4, SS5, SS10, SS14, SS15, SS18), Al-Attiyah 1 (SS11), Atkinson 1 (SS12).
(note, SS9 cancelled, SS 19 combined with SS 18)