4:40 PM PT -- Carlos' surgery went well and he was released from the hospital.

The Garden Bros Circus performer who nearly front flipped into a deadly fall during a steel pendulum act is about to go under the knife.

TMZ's learned the 31-year-old acrobat, named Carlos, initially thought he'd escaped unscathed after that nasty fall he suffered Monday night in Toledo. Carlos tells us he had a series of tests and scans immediately after the accident that didn't show any major injury.

Then on Wednesday, further testing revealed a fracture in his left foot near the ankle.

Carlos says doctors recommended surgery, requiring a plate and screws to set everything in place, and it'll be about 6 weeks before he can walk on the foot afterward. He's nervous but hopeful ... saying he plans to return to performing, because it's all he's done since he was 17.

Despite the fact several spotters failed to break his fall, Carlos says he doesn't blame anyone for the scary mishap -- he's chalking it up to timing and says it was just an accident. He doesn't really remember what went wrong ... he's just thankful he landed feet first and not on his head.

His surgery is scheduled for later Thursday, and Carlos says Garden Bros is covering the medical costs.