Six-times Olympic champion Usain Bolt broke 10 seconds for the first time this season when he won a 100m race under a closed roof at the National Stadium in Warsaw on Saturday.
The Jamaican clocked 9.98 seconds into a slight breeze at the Kamila Skolimowska Memorial in front of a 20,000 crowd on a new track laid down the side of the infield.
Bolt's first Polish outing was his third race this season as he builds up to Thursday's Diamond League meeting in Zurich and saw him set a new best time for the infrequently run 100 indoors.
The world record holder beat the previous unofficial indoor best mark of 10.05 set by Namibian Frankie Fredericks in 1996.
Bolt anchored Jamaica to 4x100m gold at the Commonwealth Games in Glasgow last month and last weekend won an exhibition race on Brazil's Copacabana beach in a time of 10.06.
His nearest rival in Warsaw was fellow Jamaican Sheldon Mitchell, who ran 10.33, but in Zurich will face three sub-10 sprinters plus Britain's European 200m champion Adam Gemili.