It was not necessarily the outcome the Braves wanted, however, as a victory for the Brewers would have seen Atlanta level with the Mets atop the NL East.
As it is, the Braves are one game back, but d'Arnaud warned their rivals they have plenty still left in the tank.
"It's a marathon, it's not over," d'Arnaud said. "So we'll just keep going after it until the end."
All-Star catcher d'Arnaud had extended his career-high home run total to 18, while William Contreras, his backup, has 19.
They are just the fourth catching duo in NL or AL history to each hit at least 18 homers in a season with at least two-thirds of their games played at catcher.
And Arnaud was effusive in his praise of Contreras, adding: "It's been so much fun.
"The energy he brings every day honestly inspires me and makes me feel young. So I don't know if I'd be having as good of a year if he wasn't here."
The Braves face the Nationals again on Wednesday, looking for a clean sweep as the Mets do likewise against the Brewers.