The 27-year-old scored the only goal in Sunday's 1-0 victory over Liverpool, turning in Rice's delivery in the 16th minute to give Mikel Arteta's side a landmark result. Arsenal had not won a Premier League match at Anfield since September 2012, ending a run of 13 visits without a victory.
Havertz was delighted to help bring that sequence to an end, recognising the significance of the achievement for the club and its supporters.
"It means a lot to the whole club, and it's been 14 years. That's an incredible statistic, and I think we're all happy that we were able to give them that today," he said.
The forward also acknowledged the difficulty of winning at Anfield, where Liverpool's players and supporters can make life uncomfortable for visiting teams.
"I think we all know what this stadium is like and what the fans are like. Liverpool have great players, and they can show their quality. We knew that was coming for us, and we all stuck together and defended together."
While Havertz supplied the finish, he was keen to direct most of the credit towards Rice, whose run and low cross created the opportunity.
"90 per cent of the goal belongs to Declan Rice," he told Sky Sports after the match.
The goal carried an additional personal milestone. Havertz moved to 46 Premier League goals, overtaking former Manchester City midfielder Ilkay Gündogan, who had held the record for the most goals by a German player in the competition with 45.
Havertz has scored 19 of those goals during his time at Chelsea and 27 since joining Arsenal. His finish at Anfield therefore made him the outright record-holder, adding another achievement to an afternoon that had already delivered a significant result for his club.
The victory also lifted Arsenal to the top of the Premier League table, with 24 points from nine matches and a three-point advantage over Manchester City.
Liverpool applied considerable pressure after falling behind, but Arsenal held firm to protect their lead. Havertz's goal proved decisive, while the collective defensive effort ensured the Gunners finally left Anfield with a league victory.
For the German, the personal record was welcome, but the end of the long wait mattered most.