Horstmann admitted it was a night of high emotion at the home of the Warriors and was quick to praise the role of the home fans who created a wonderful atmosphere before wild scenes of celebration greeted the final whistle.
"The crowd was simple sensational tonight," said Horstmann. "That is the best atmosphere I have ever experienced at Sixways. Hats off to every fan that came through that door because they were unreal.
"It's a phenomenal feeling. A mixture of real relief and great satisfaction," he added.
"We're pleased it is over and delighted to be back in the Premiership. It's been such a long season for everyone involved, right across the whole club.
"We're now massively excited and already looking forward to being back in the top-flight.
"It's sad to see a few big characters leave and guys like Adam Black and Greg Rawlinson play one last game.
"But we're excited about what the future holds back in the big time. It's a few well deserved weeks off and then we are back to it and we go again in the Aviva Premiership."