The University of Hong Kong was forced to abort a demonstration of "Atlas" - its state-of-the-art humanoid robot - after it lost its balance and broke its right ankle.
The embarrassing moment was captured by dozens of journalists invited to see Atlas show its ability to walk through obstacles and point at objects.
The nearly two-meter tall robot made of aluminum and titanium, is one of the most advanced of its kind. There are only seven in the world and the university has the only one in Asia.
Atlas first demonstrated tai chi using slow and smooth movements to music, despite its 150-kilogram body.
A computer showed what it could see through its eyes - leaving everyone gasping.
However, when it tried to step over and cross an obstacle, it stumbled.
It failed again while trying to point at objects and broke its ankle.
"Please forgive him. He's just a baby trying to learn," said project leader Wyatt Newman.
Newman said Atlas had earlier broken its left ankle and an expert had to be flown in from the United States to fix it.
Researchers said it is designed to simulate natural human movements, and is expected to work in hazardous environments, such as oil rigs and mines, and to clear debris after earthquakes.
The team is developing and refining the robot's software brains and nerves which will guide the suite of sensors, actuators, joints and limbs that make up its actions.
Norman Tien, dean of engineering at the university, said robotics is one of the strategic themes of the Faculty of Engineering.