Ireland's Daniel Wiffen posted the fastest time in the heats for the 800m freestyle on Monday, and the world champion now has his sights set on making history in Tuesday's final.
Wiffen could become the first Irishman, and just the second Irish athlete ever, to claim Olympic swimming gold – and his hopes were boosted with challenger Sam Short of Australia, considered the favourite by some analysts, failing to qualify.
The 23-year-old Wiffen topped qualifying in 7:41.53, ahead of Tunisia's Ahmed Jaouadi.
But he will also need to hold off defending Olympic champion Bobby Finke of the United States, in-form Australian Elijah Winnington and experienced Italian Gregorio Paltrinieri, Tokyo silver medallist, in an open field.
"Any lane has a chance, I'll be looking at everybody, I'll be doing my homework tonight, seeing how everybody swims it, and I'll be making sure that I'll be one of the best there tomorrow night," Wiffen told reporters.
Michelle Smith's three golds and a bronze from the Atlanta Games in 1996 remains Ireland's only Olympic medals in swimming.
But Wiffen, was born in Yorkshire, England, before moving to County Down in Northern Ireland at the age of two, says he isn't fixated on the gold.
"Any medal's good, it's my first race here, and it's my first time actually being in contention for an Olympic medal, so I'll take any medal, whatever colour," he said.
Wiffen is in his second Olympics, having entered the 800 and 1500 metre races in Tokyo, but after his rapid rise in the sport he says there is little comparison.
"It is completely different. In Tokyo, I was just really qualifying and trying to keep progressing. The past three years have been a blast for me – I've been dropping 16 seconds every time I've swam in the water in the 1500, and I've been PB-ing every single international, I just want to keep that streak up here," he said.
The heats, held in the morning, have drawn impressive crowds and Wiffen says the noise they generate is felt by the swimmers.
"I very rarely hear the crowd when I'm swimming but this one I can hear 100 per cent. There's a lot of Irish support, I saw a lot of tricolours in the stands, so pretty happy," he said.
He is making the most of these Games – as well as the two races at the La Defense Arena, he also plans to race in the 10km open water race in the River Seine.
It is a heavy workload, but Wiffen says he is the fittest he has ever been, describing himself as "100 per cent."
"Never been in this shape before in my life".