Sebastien Ogier extended his lead over Dani Sordo to 4.4 seconds after finishing second-fastest on the superspecial that closed Friday's Rally Portugal running.
The Volkswagen driver found two seconds on his Citroen rival over the 3.27 kilometre Lisboa stage.
Sordo had earlier closed by more than eight seconds over SS3 and SS4, with Ogier admitting his decision to select soft tyres all round was "not perfect." Ogier also complained of a "small problem" which had tempered his approach to the superspecial.
Sordo's Citroen stablemate Mikko Hirvonen won the stage, finishing 0.9sec ahead of Ogier. In doing so he closed to within 4.8s of Jari-Matti Latvala, who was third on Friday's final stage.
Thierry Neuville drifted away from the podium fight in fifth, 30sec down, but he enjoys a comfortable gap to a chasing pack led by M-Sport teammates Evgeny Novikov and Nasser Al-Attiyah. Martin Prokop, meanwhile, jumped ahead of the Mini of Michal Kosciuszko and into eighth.
Kosciuszko had to contend with a loose hood after dislodging it over a jump early on in the superspecial.
Robert Kubica didn't even make it to the start of the stage, the Pole retiring from second in the WRC2 standings after running out of tires (see separate story).
Leading positions after SS5:
Pos Driver Car Time/Gap
1. Sebastien Ogier Volkswagen 46m38.5s
2. Dani Sordo Citroen + 4.4s
3. Jari-Matti Latvala Volkswagen + 11.4s
4. Mikko Hirvonen Citroen + 16.2s
5. Thierry Neuville M-Sport Ford + 30.7s
6. Evgeny Novikov M-Sport Ford + 1m17.0s
7. Nasser Al-Attiyah M-Sport Ford + 2m16.4s
8. Martin Prokop Czech Ford + 2m27.9s
9. Michal Kosciuszko Italia Mini + 2m37.1s
10. Dennis Kuipers M-Sport Ford + 2m48.7s