TOKYO, July 31 (Reuters) - The post-Usain Bolt era in the men"s Olympic 100 metres began on Saturday in Tokyo, with Dorian Keletela, who is competing in the Games as part of the Olympic Refugee team, advancing to the next round with a personal best performance of 10.33 seconds. Jamaican Bolt won three straight titles beginning in Beijing in 2008 but since his retirement in 2017, nobody has really emerged to stamp their authority on the showpiece of athletics. On Saturday, amid stifling temperatures that hit 31 degrees Celsius, sprinters took the track as they began their attempts to succeed the world-record holder Bolt. Keletela, 22, is one of those athletes. Originally from the Democratic Republic of the Congo, he moved to Portugal in 2016, following the death of his parents due to conflict in his homeland and ran a personal best 10.33 to advance to the next round later on Saturday. Others who progressed from the preliminary heats include Zimbabwe"s Ngoni Makusha, who got off the block fast to win his heat in 10.32 and Oman"s Barakat Al Harthi who posted 10.27s to win his race. There were three preliminary heats overall and the first three in each heat qualify to round one, along with the next sprinter who is fastest. Later on Saturday, other fast men on earth will join the race to hunt for Bolt"s mantle, and the United States, who have won more golds in the event than all other nations combined, will aim to work towards regaining their supremacy. read more Their last gold medal win in the event came via Justin Gatlin in 2004. Contenders include Trayvon Bromell, whose 9.77 second run in Florida last month is the fastest of the year and propels him into the top tier of favourites in the race. His compatriot Ronnie Baker is probably his closest rival for podium positions and finished second to him at the U.S. trials with a time of 9.85. Canada"s Andre De Grasse, who won bronze in the 100m in Rio five years ago, will be looking to go for the title this time around while South African sprinter Akani Simbine, fifth in Brazil and boasting the second fastest time of the year, will have something to say as well. While there hasn"t been a Jamaican to step up and succeed Bolt, his running partner Yohan Blake, now 31 and the 2012 silver medallist and second-fastest man in history, will carry his nation"s hopes on his shoulders. Reporting by Omar Mohammed; Editing by Muralikumar Anantharaman