Seventh stage win
The Overdrive Racing man was the first driver to pass the next checkpoint after 165km in 2hrs 04min 21sec. The Qatari was 45 seconds faster than Matthieu Serradori with Van Loon in third place and Ming Zhang in fourth.
Al Attiyah continued to lead through the subsequent checkpoints to claim a seventh successive stage win, but Kun Lui dropped serious time midway through the special and ceded his second place overall - a position that was taken by Frenchman Jerome Pelichet.
Extends lead
Al Attiyah had claimed a sixth successive stage win on the 408.15km section between Mandalgovi and Dalanzadgad in Mongolia.
The Qatari looked to be in a vulnerable position after the crew made a rare navigational mistake, but all the Toyota's leading rivals followed suit and made a similar error and that enabled the Qatari to snatch the stage win by 3min 15sec from Overdrive Racing team-mate Van Loon.
Right way
The day also saw the Hilux crew extend their overall lead over China's Kun Lui to 40min 33sec.
The Qatari said: "Sometimes navigation is not easy and the sixth stage was one of those days. We were never lost, we just had to go back a few hundred metres to find the right way."
No special stage
There was no special stage on the seventh day. Two liaison sections of 370.37km and 180.29km took crews to the border between Dalanzadgad in Mongolia and the China frontier and on to the night halt at Bayinbaolige in China's Inner Mongolia.
On Monday (July 15) teams tackle the ninth and penultimate stage between Alashan and Jiayuguan. In a day's route of 501.20km, teams will tackle 290.30km against the clock.