It was a perfectly executed forward roll - even better for the fact that this panda managed it in his sleep. Tai Shan, a 4-year-old male at National Zoo was sitting in his zoo enclosure when he began to doze off, his eyes flickering open and shut before he succumbed to sleep and slumped forward. The sleepy panda could have fallen flat on his face. But instead he popped his head between his legs and turned head-over-heels before landing on his back. It's been a long day! Giant Panda Tai Chan takes a doze in the midday sun If pandas can look surprised, then four-year-old Tai Shan certainly did at that moment. Tourists at the National Zoo in Washington DC, who saw the four-and-a-half-year-old panda roll off the kerb only to recline in the grass, were delighted by his impromptu gymnastic skills. Easy does it! Tai Shan leans his head on the ground and then performs a perfect roly-poly The classic moments were caught on camera by visitor Judy Young, 61. Judy said: "A lot of people were watching him when he just suddenly fell forward and performed this forward roll." British tourist Mary Taylor, 36, said: "He kept closing his eyes to the point where he nodded off. Close up! Tai Shan bears his claws as he rolls off the edge of the paving "He then slumped forward and I thought he was going to land flat on his face. "But he must of woken himself up at the last moment because he turned it into this perfect roly-poly." Eye opener: The Giant Panda wakes up to a slightly different view Tai Shan is the only panda born at the zoo that has survived. His parents Mei Xiang and Tian Tian were donated to the zoo by the China Research and Conservation Centre for the Giant Panda in Sichuan Province. Surrender? Tai Chun looks literally bowled over - but pleased to give in His mother was artificially inseminated in 2005 after natural mating between her and Tian Tian failed. Unperturbed: Tai Chan reclines against the kerb