Craig Breen finished sixth at the Safari Rally Kenya as Finland's Kalle Rovanpera lead a Toyota sweep of the top four places to stretch his World Rally Championship lead to 65 points.
The last time Toyota managed a 1-2-3-4 finish was at the same event in 1993 won by Juha Kankkunen.
Welsh team-mate Elfyn Evans finished second, 52.8 seconds behind the 21-year-old Rovanpera, and Japan's Takamoto Katsuta, along with his Northern Irish co-driver Aaron Johnston, secured third.
Eight-times world champion Sebastien Ogier was fourth ahead of Hyundai's Thierry Neuville.
Waterford native Breen and his co-driver Paul Nagle were 23:27.9 adrift of first place and are now fifth in the championship standings for the M-Sport Ford team on 60 points.
"I have to say, this was the hardest rally I have ever done," said Rovanpera, who battled through mud and torrential rain on Saturday and took his fourth win in six rounds to sit on 145 points.
"To have four cars like this with no issues; it is clearly the strongest and fastest car. The team did a fantastic job."
Neuville, who is second in the championship, won the final 'Hell's Gate' Power Stage for five bonus points.
Nine-times world champion Sebastien Loeb, competing in the Safari for the first time in 20 years, took four bonus points for Ford ahead of last year's winner Ogier.
Toyota are 62 points clear of Hyundai after six of 13 rounds.
Sunday featured three stages, each run twice, on the southern edge of Lake Naivasha.
Additional reporting: Reuters