For 2017, Elfyn rejoined the M-Sport World Rally Team to drive the DMACK car. He started the year with sixth in Monte Carlo, setting several fastest stage times, and then repeated the performance in Sweden. After two disappointing rounds in Mexico and Corsica, at round five in Argentina, Evans benefited from misfortune for his rivals to end day one with a minutes lead. On day two, Evans struggled with punctures, a spin and a damaged diffuser, and saw his lead fall to just 11 seconds. On the final stage, it was a straight battle between him and Hyundai driver Thierry Neuville. He pushed early in the stage, but lost several seconds when he hit a bridge. He tried hard to make up the lost time, but in the end he lost his first victory by just 0.7 seconds to Neuville. In Finland, Evans was left to uphold team honors after a crash for teammate Sébastien Ogier and a puncture for Ott Tänak. He dutifully set consistent top three stage times and snatched second place on the last stage from Juho Hänninen, in what many journalists described as the best drive of his career so far. At the penultimate round on his home rally in Wales, Evans took advantage of his DMACK tyres, which were widely suited to the conditions, to take his first WRC win, the first for a Welsh driver, and the first for a British driver on Wales Rally GB since the late Richard Burns in 2000. He would finish the championship in fifth place.