The Škoda Fabia driver edged series leader Yohan Rossel in a thrilling battle for victory at the Matosinhos-based event to climb to second in the points.
Kajetanowicz’s Portuguese success came on the back of a Croatia Rally victory last month, but Sunday’s win was special, given that it was his debut on Europe’s westernmost WRC round.
The Polish star said: “It has been a great weekend. It has been even better than Croatia. This is a debut for me on this famous rally, [it’s good] because so many drivers know this rally well, while Croatia was new for everyone. I made only one mistake here and I lost a maximum of 20sec.
“What can I say more? I am smiling, believe me.”
Video: Vodafone Rally de Portugal WRC3 highlights
Kajetanowicz offered an emotional response to the feeling of crossing the line as a winner for the second time in as many rallies.
He said: “A driver and co-driver know the feeling in this situation. It is amazing. You cannot compare it to nothing, this feeling. You need to keep calm and, at the same time, the pressure is really high. At the end of the last stage, I thought: ‘I love this feeling. In the future I will miss it, for sure.’ ”
Kajetanowicz’s second WRC3 win in four weeks was impressive, but he was full of admiration for WRC2 winner Esapekka Lappi, who was close on five minutes ahead in a similar Rally2 category car.
“I am still so far from these guys,” he said. “They have a fantastic speed.”
His opportunity to challenge for a WRC3 hat-trick comes next week, when he starts Rally Italia Sardegna.
“It’s a short time to this rally,” he said, “but I will be ready. I have experience there. But many drivers know this rally. It is going to be very difficult.”