Muller dominated the second leg of the Portugal double header from pole position, leading every lap outside of the pit cycle en route to a lights-to-flag victory.
It marked the first DTM race win for Muller since the 2020 season finale at Hockenheim, with both the Swiss driver and Team Rosberg having struggled for competitiveness following the series' switch to GT3 cars last year.
Muller said he was relieved to end his victory drought in the opening round of the 2022 season, feeling the work put in by his team during the winter is already paying dividends.
"Last year was tough - very, very tough and turning around during the winter feels very good," said the Swiss driver.
"When you go testing, you think you're going in the right direction but you're never really sure.
"You're driving around in circles by yourself and kind of hope that what you're doing is right. I'm just relieved our feeling didn't mislead us.
"I think we just managed to hit the sweet spot and the optimum working window of our car. And I felt very confident and comfortable since Friday in the car, especially on a single lap."
Although Muller took pole position by over two tenths and was virtually unchallenged in the 33-lap contest on Sunday, the rest of the pack was closely matched in both qualifying and Sunday.
There was only a three-tenth gap between Grasser Racing's Mirko Bortolotti and Abt Audi driver Rene Rast in the 20-minute pole shootout and yet the Lamborghini driver qualified on the front row alongside Muller while the three-time DTM champion was left a disappointed 13th on the grid.
In the race itself, all six manufacturers were represented inside the top seven, with seventh-placed Laurens Vanthoor finishing just six seconds off the podium in a race that featured no safety cars or full course yellows.
Taking into account how competitive the DTM is proving to be in its second season under GT3 regulations, with a total of 29 drivers taking part in the series, Muller felt it was important for him to maximise his chances when he had a car capable of scoring a race win.
"I feel like the days where you have the package to win, you need to grab it with both hands," said the Swiss driver, who finished runner-up to champion Rast in both 2019 and '20.
"It's so levelled out that you will not get that many opportunities to win races and when you are in a position you wanna really do it.
"It will be about limiting the damage when you cannot win and on a day like Saturday. That's what my other Audi colleagues managed to do and we got taken out of that game.
"But luck will turn around and consistency will be the deciding factor this season. We need to maximise when you have the package."
Bortolotti not getting carried away after double podium
With Muller having been forced to retire from the opening race at Portimao due to a puncture, he sits second in the championship behind DTM newcomer and factory Lamborghini racer Bortolotti.
The Italian driver led Saturday's race from pole position until a fuel injection issue struck his Lamborghini after a safety car restart, leaving him third at the finish behind the Mercedes duo of Lucas Auer and Luca Stolz.
He replicated that result in Sunday's second race of the weekend after starting from the front row, finishing just behind Muller and Red Bull's Felipe Fraga to take an early seven-point lead in the championship.
Bortolotti said his goal remains to win the title in his first full season in the DTM, but stressed that he will have to be consistent to remain in the championship fight until the end of the season.
"It's too early to say but there are many drivers capable of winning the title this year," said Bortolotti.
"I've always said from the beginning that consistency is definitely important. And from our side, from my personal side, it's our ambition to be in that fight and to fight for it until the end, hopefully to be in the same position [as now] after the last race.
"We had a great start to the season, [but] it could have been better on Saturday. As Nico said when you have the chance to take the big points and win the race you have to take it.
"Unfortunately, that [fuel injection issue] cost us a little bit on Saturday. But at the end of the day we go home with the points that we deserved to score after Sunday's results, which feels better than what we should have been capable of scoring.
"So I'm really happy at the end of the day with the points we've scored this weekend."
