The championship leader could afford to back off during the pair of stages, ending the loop with a 1m29.2s lead over title rival and team-mate Elfyn Evans, who snatched second from Hyundai's Dani Sordo.
Sordo started the morning in second spot but trailed Evans by 2.7s heading into the final stage.
M-Sport's Ott Tanak maintained fourth (+4m25.8s) ahead of Hyundai's Esapekka Lappi (+6m18s) and Toyota's Takamoto Katsuta (+7m09.5s).
Andreas Mikkelsen overhauled Gus Greensmith to claim seventh and the WRC2 lead.
The hot and dry weather conditions continued as the rally resumed on Sunday morning and, after a brutal Saturday, reaching the finish was the key target for Rovanpera.
Having witnessed all of his Toyota team-mates suffer punctures or mechanical issues, the Finn engaged preservation mode having started the day with a 2m04.4s lead over Sordo.
Rovanpera admitted that it was "not so easy when you don't have any pace and a proper rhythm," but was relieved to complete stage 13 (Tarzan, 23.37km), albeit 31.2s adrift of the outright pace.
That pace was delivered by his championship rival and team-mate Evans, who was locked in a close fight for second with Sordo.
The Welshman managed to take 9s out of his Hyundai rival, who was struggling on soft rubber, to leapfrog the veteran Spaniard.
Thierry Neuville clocked the third fastest time after rejoining the action after retiring from the lead on Saturday afternoon.
Source: Autosport