Geraint Thomas swapped baseball mitts for his racing cleats before being edged out in the home run in Japan.
The Cardiff-born rider was beaten in a sprint finish by world road race champion Alejandro Valverde in the exhibition criterium in Saitama.
The Tour de France champ had only trained for a few days in Wales having had a post-season break following his historic exploits this year.
“It was hard at first and so I just tried to survive,” said Thomas, who competed on his yellow Tour de France bike.
“I felt better later and so waited for the final quarter of the race. Valverde is fast in a sprint and so there wasn’t much I could do there.
“The main thing was to enjoy the race. The crowds were so big that it reminded me of racing in the UK.”
The holder of the Yellow Jersey traditionally takes part in the event with the pre-race build-up seeing Thomas trying his hand at baseball – a sport huge in Japan.
Thomas and his Spanish rival – the two headline riders in the exhibition criterium – got away in the final laps of the 3.1km Saitama circuit.
The duo were joined by home rider Yukiya Arashiro (Bahrain-Merida) but he faded in the final kilometre, leaving Valverde to take on Thomas after the final corner.
Despite racing in leg warmers, Valverde opened a gap on the Welshman in the kick for the line and won by several lengths and celebrated with his arms in the air.
“It’s great to win here. This is my first victory in the rainbow jersey, so I’m very happy,” Valverde said.