The 27-year-old says that the team are one step closer to winning the competition, while crediting his team-mates for their role in his hat-trick versus their city rivals
The Portugal international grabbed his seventh hat-trick of the 2011-12 Liga season, before Jose Callejon helped to make the result even more expressive with a goal of his own. Radamel Falcao had earlier drawn Atleti briefly level.
The victory allowed Madrid to maintain the four-point gap between themselves and Barcelona at the top of the table, and Ronaldo believes that his side have taken an important step towards winning the league.
"There is a lot left, but winning La Liga has got closer now. Losing is not in my vocabulary," Ronaldo told reporters.
"There was pressure on us because we knew Barcelona had won their match. We are still four points clear."
Ronaldo then expressed his happiness to have taken his league tally to 40 goals following Wednesday's hat-trick.
"I am very happy to have scored and picked up an assist," he noted. "We have to continue like this.
"I am very happy, but without my team-mates I could not have done it.
"We knew this was going to be a tough match, but we gave a good account of ourselves against a very strong Atletico side."
Cristiano Ronaldo has now scored 52 goals in all competitions following Wednesday's hat-trick, and became the first player to score 20 goals away from home in a single Liga season.