RIO DE JANEIRO - As Usain Bolt churned down the track during an early race at the 2016 Rio Olympics, his main rival was trying to get in front of a TV monitor to catch a quick glimpse of the race.
Justin Gatlin missed the Jamaican's first-round heat. That's OK, the American sprinter has seen plenty of Bolt to know exactly what to expect.
Bolt is a huge favorite to win an unprecedented third straight Olympic title in the 100 meters on Sunday evening. And that's despite pulling out of the Jamaican trials last month because of a sore hamstring and wishing he had more races coming into Rio de Janeiro.
It certainly hasn't changed his focus.
"It's always to win. That's what I'm here for," said Bolt, who was 3-for-3 in races at the 2008 Beijing Games and again four years later in London. "That's what I'm going for. My focus is to go out there and do my best, and execute well."
Bolt posted the fourth-fastest time in the first round (10.07 seconds), with Gatlin leading the way (10.01).
Gatlin has the best odds to unseat Bolt in the 100m (8/5) and 200m (3/1).
However, Jamaica is still expected to dominate with Bolt favored in the 100m (1/2) and 200m (4/13).
Lately, Gatlin is the only one who's been remotely close to keeping up to Bolt. He nearly beat Bolt during the 100 final at the world championships in Beijing last August, but faltered at the end. The 34-year-old Gatlin was neck-and-neck with the Jamaican, but over-strided with about 15 meters left and went into his lean too early. That paved the way for Bolt to capture gold.
A mistake Gatlin took to heart.
"A win or a loss - they're all lessons you learn to become a stronger athlete, a stronger human, the next time around," Gatlin said.
With his doping past, Gatlin has been portrayed as the villain in his rivalry with Bolt, which has become track's version of "Good vs. Evil." He doesn't care what anyone thinks.
"I've worked hard like everybody else," Gatlin said. "I get tested like everyone else. I'm back here. I believe in the system. I hope everybody else believes in the system, too."
His name almost always comes up in the debate over how past dopers should be treated. In Rio, it surfaced in the wake of American swimmer Lilly King's finger-wagging display toward Yulia Efimova, the Russian who was allowed to compete after a last-minute appeal to the Court of Arbitration for Sport.
Like Gatlin, Efimova has served a doping ban but was reinstated.
But in refusing to bar the entire Russian team from the Olympics after investigations detailed state-sponsored doping in the country, the IOC put in a special caveat: Any Russian who had been previously banned for doping was not welcome.
That rule was overturned by CAS, which had made similar decisions in previous cases, saying athletes can't be punished twice for the same offense.
King's criticism of Efimova -- and her icy stares toward the Russian before the two squared off in the pool - instantly made King a voice in support of clean athletes everywhere.
The dispute led to King, and many others, being asked if it was fair that Gatlin was competing.
"Do I think people who have been caught doping should be on the team? They shouldn't. It is unfortunate we have to see that," King said.
But, King said, she had to respect the rules.
Knocking off Bolt is a tall order. Asked how a sprinter upsets Bolt, veteran Churandy Martina of the Netherlands pondered his response for a moment.
"To beat Bolt? Oh," said Martina, who didn't make it out of the first round. "Once he's in a tight position, he might tense up. But you never know, because he always shows up at the right time and the right moment, which is these games."
Here are some others - besides Gatlin - who can interrupt Bolt's run at greatness:
YOHAN BLAKE: Bolt's teammate is rounding into shape after dealing with hamstring and leg injuries in recent seasons. Blake finished runner-up to Bolt in both the 100 and 200 at the 2012 London Games.
ANDRE DE GRASSE: The 21-year-old Canadian went to Southern Cal and split the bronze medal at the 2015 world championships with American sprinter Trayvon Bromell.
BROMELL: His career was nearly over before it even got to the starting line. He severely injured his left knee on a back flip gone wrong in eighth grade, damaged the right knee while grabbing a rebound during a basketball tournament in ninth grade and cracked his hip in a 100-meter race as a sophomore. He was all set to give it up, before his mom convinced him to keep going. A fruitful decision. He turned pro last fall after two NCAA titles at Baylor, hired the same agent as Bolt and signed a shoe deal with New Balance.
XIE ZHENYE: The 22-year-old from China was a world youth champion at 200 meters in 2012. He ran the second leg on the Chinese team that captured the silver at the worlds last year in Beijing.
BEN YOUSSEF MEITE: The 29-year-old from Ivory Coast is a dark horse. He did have the second-fastest time in the first round (10.03).