Al Attiyah had won his third successive section with a stage win on the 243km stint into the Mongolian capital of Ulaanbaatar.
The Overdrive Racing Team driver finished the special 6min 13sec in front of Russia's Denis Krotov, despite a flat tyre, and extended his outright lead over China's Kun Lui to 21min 10sec.
The Qatari said: "Whenever we find ourselves in good conditions we try to push. We were trying to make a gap at the front. It is never easy to open the track but I trust my co-driver Matthieu."
On Friday (July 12), the teams tackle a special stage of 408.15km in a day's route of 411.75km between Mandalgovi and Dalanzadgad in Mongolia.
Longest timed section
The fourth special comprised a loop around the vast terrain to the east of Ulaanbaatar.
In a day's route of 476.96km, 470.19km were timed against the clock in the longest timed section of the entire event.
The year's Silk Way Rally is a candidate race for possible future inclusion in the FIA World Cup for Cross-Country Rallies. The event finishes in Dunhuang on July 16.
"We did a good job on this long stage. There was no problem with the car and Matthieu did a good job with the navigation. We enjoyed the Mongolian landscape. It really was incredible. We are happy to be doing well at this rally," Al Attiyah added.