By Martyn Herman
TOKYO (Reuters) -Colombia's BMX queen Mariana Pajon began her quest for a hat-trick of Olympic titles on Thursday exactly how she left off in Rio five years ago - looking invincible.
Pajon won all three heats of her quarter-final group and while it is impossible to glide around the snaking circuit in such a high-tempo sport, she looked supremely smooth.
American Connor Field, like Pajon coming in as Olympic champion, also made a commanding start at a baking-hot Ariake Urban Sport Park, winning two of his races and placing second in the other to roll into Friday's semi-finals.
"I'm feeling really confident," Pajon told Reuters. "I'm just grateful that I'm here again after everything I've been through."
The 29-year-old from Medellin suffered torn knee ligaments in a World Cup crash in 2018 and while she is no stranger to injuries having suffered 18 fractures in her career, it did threaten her Tokyo hopes.
But she looked as strong as ever on Thursday, landing all the jumps perfectly and powering round the curves.
In Rio she became the first rider in the history of a sport introduced to the Olympics in 2008 to win every race on the way to gold,
"It's a very different story this time with no fans and a strange preparation, but I'm doing my best. We have a great team and it's a dream to have my husband around, it's all just good energy so far."
Her husband is fellow BMX racer Vincent Pelluard who she married in 2017, and who now rides for Colombia having switched allegiance from France. He also made the men's semi-finals.
American Alise Willoughby matched Pajon's 100% record for the day as she topped her quarter-final group in style.
Willoughby, second behind the Colombian in Rio and who is married to her coach, Australian great Sam Willoughby, said it was a case of "doing what you have to do" to make sure of a semi-final place.
"Just trying to run clean laps and figure out my lines," she said. "Got a little bit of everything out there today and I'm excited for tomorrow."
Field, in what could be his last Olympics, said he was happy with a solid start.
"It's all about advancing to the next round with the Olympic format," the Las Vegan, who brushed off the heat, said. "Looking forward to tomorrow and repeating the process."
Blocking Fields' path to a second Olympic medal will be two Frenchman -- Joris Daudet and Andre Sylvain who both claimed three wins in the quarter-finals.
"There are a lot of contenders for gold and I think the smartest and the fastest will be the one to win, so I will do everything to be that guy," Sylvain said.
Of the 24 riders who started in the men's and women's event on Thursday, eight were eliminated in each with Japanese female rider Sae Hatakeyama's Games lasting only a matter of seconds as she crashed in her first heat and broke her collarbone.
The top four riders from the three-race semi-finals will progress to the final.
(Reporting by Martyn Herman; Editing by Stephen Coates & Shri Navaratnam)