Sebastian Vettel deservedly took all the limelight after his victory in the Indian Grand Prix saw him become the sport's youngest ever four-time champion - beating the likes of Juan Manuel Fangio, Alain Prost and Michael Schumacher to that milestone.
Yet every bit as important to Horner was sealing the award for the best constructor, which the Milton Keynes-based outfit have now won every year since 2010, again seeing off the might of Ferrari, McLaren and Mercedes.
"To achieve four double world championships is the culmination of an enormous amount of dedication and commitment from the whole team," said Horner, whose Adrian Newey-designed cars have won 10 times this season in the hands of Vettel.
"For Sebastian to have joined the illustrious names of Fangio, Prost and Schumacher is an incredible achievement, especially at such a young age and it's a privilege to work with him.
"It's an enormous day for the team to have won its fourth consecutive constructors' world championship."
The day fell just short of being a perfect for Red Bull when the sister car of Mark Webber retired with an alternator problem at two-thirds distance, denying the team a one-two finish.
"The most disappointing thing today was obviously the failure on Mark's car," Horner said.
"We had a sudden alternator failure, but sometimes that's racing. It was just desperately disappointing to happen while we were on course to achieve a one-two finish."
Webber, who now has just three more races for Red Bull before he moves on to a new challenge with Porsche in sports car racing, added: "Obviously
I'm pretty disappointed with today's race, but there is not much I can do, the alternator went wrong with very short notice so we had to stop straight away.
"It's tough because we did a lot of things right this weekend, but I've got a smile on my face as I could not have done any more.
"Well done to Seb on his championship and also to all the team; to get a fourth title is amazing. It's been a great job by the whole team to achieve the title four years on the trot and it has once again set itself as the benchmark for the others."