Guests were stranded on the ride after one of the carriages became stuck on the tracks moments before it descended on its stomach-churning 180ft vertical drop.
Rescue teams wearing helmets and safety ropes scaled the ride and handed stranded riders bottled water as temperatures soared to 37c at the Staffordshire theme park.
They were then fitted with harnesses before being led down steps to safety.
One guest called Dean posted pictures of the rescue and provided updates on Twitter.
He tweeted: “A Oblivion shuttle has stopped at the top, I’m sure the magical bottles of water will be straight out in this heat!
Dean added: "Guests are now being evacuated from the top, they have remained safe throughout the evacuation, with bottled water provided, and a harness to walk back down to the ground!"
After the rescue, the park described the process as a "routine stoppage" as it sought to reassure guests.
A spokesman for Alton Towers said: "Oblivion experienced a routine stoppage. The ride performed exactly as it is designed to do.
“In line with our well-rehearsed procedures, guests were assisted from the ride and were immediately given water, food, hats and all left happy to continue on with their day at the park.
"At no point was guest safety compromised.”
The park added that it was taking measures to keep visitors as safe and comfortable as possible during the UK’s record-breaking heatwave.
It said: "We are aware of the forecast of hot temperatures in the coming week and will be taking the appropriate precautions to ensure our guests can continue to enjoy a magical and safe day out our attractions.
"The health and safety of our guests and staff is our number one priority so our attractions will be operating with additional precautions for the hot weather, including free water top ups and sun cream located at multiple points across the park, as well as additional water bottles and welfare breaks for our staff.
"Each Merlin attraction has a different set of experiences and our dedicated Health & Safety teams will continue to monitor the situation.”