Tiangong Ultra lowered the sprint mark for a second straight day, while crashes beyond the finish line underscored the gap between fast demonstrations and dependable workplace robots.

BEIJING — A humanoid robot called Tiangong Ultra ran 100 meters in 8.64 seconds on August 26, setting a new mark at the World Humanoid Robot Games in Beijing and improving on records set earlier in the five-day competition.

The same model had run 8.86 seconds the day before, after posting 9.39 seconds at the start of the games. More than 2,000 humanoid robots took part in the event’s second edition, competing in sports including running, soccer and boxing, as well as tasks modeled on housework, hotel service and emergency response.

The sprint finale also highlighted the machines’ limitations. Several robots, including the winner, hit a padded barrier after crossing the line. Some produced sparks and were attended to with fire extinguishers before being removed from the track.

The speed results surpassed the 9.58-second men’s human world record held by Usain Bolt, but the events are not equivalent athletic contests. The robot races took place in a controlled setting, and Reuters reported that industry executives and researchers say current humanoids still struggle with the adaptability, dexterity and reliability needed for broad, general-purpose work.

The games included practical challenges such as industrial assembly, material handling, EV charging and restaurant work. Those tests, rather than headline sprint times alone, are intended to gauge whether humanoid robots can complete useful tasks without frequent human intervention.