Katie Ledecky won the 200m freestyle to complete the first half of a daunting double at the US Olympic swimming trials on Wednesday that concludes with the 1,500m free final.
Ledecky, added the 200m to the 400m free victory on Monday, giving herself a chance to defend two of the titles she won in Rio de Janeiro in 2016.
Trailing Allison Schmitt at the halfway mark, Ledecky surged home to win in 1min 55.11sec with Schmitt, the 2012 Olympic gold medallist, second in 1:56.79 to put herself in line for a trip to Tokyo.
Ledecky had little more than an hour before she was due on deck for the 1500m freestyle final, the two events representing the toughest daily double she will face as she targets a formidable array of events in the 200m, 400m, 800m and 1500m freestyles.
The heats, 200m semi-finals and finals of the two events require her to race 3,600m in less than 36 hours.
"I just take it one day at a time," said Ledecky.
She has tackled the 200m-1500m double at the World Championships, winning gold in both in 2015 and 200m silver and 1500m gold in 2017.
Her first shot at it in the Olympics comes thanks to the addition of the 1500m free as an event for women at the Games for the first time this year.
Ledecky had already punched her ticket to Tokyo in the 400m freestyle on Monday.
Her winning time of 4:01.27 was nothing special, but Ledecky said that even with five gold medals from two previous Olympics, she had felt the nerves upon returning to trials and racing in front of fans for the first time in years.
"The first race is always the toughest," she said. "There's just that added level of excitement and nervousness. I just wanted to get the race over with and get to the wall and punch my ticket.
"There are always expectations out there," she added. "(But) the most important expectations are the ones that I have for myself.
"I think I do a pretty good job of sticking to those and not seeing what kinds of medal counts or times that people are throwing out about what I could accomplish if everything goes perfectly.
"I just have to stick to my own goals, and that's what I do."