Group Andre Agassi will get its start on Monday, as the Nitto ATP Finals moves into its second day of group stage play in London.

ATP Finals Nadal Medvedev
Dominic Thiem upset Roger Federer on the first day of the Nitto ATP Finals in London. (Image: AFP)

Monday’s ATP Finals will see Daniil Medvedev take on Stefanos Tsitsipas in the early match, followed by Rafael Nadal vs. Alexander Zverev.

Medvedev, Nadal Undefeated vs. ATP Finals Rivals

According to BetWay, Medvedev is a 4/9 favorite over Tsitsipas (9/5). The two young stars have played five times so far on the ATP Tour, with Medvedev having won each and every one of those encounters. Not only that, but the Russian has had a breakout season, winning two Masters tournaments, and reaching the final at the US Open in September.

All of that has many believing that the 23-year-old Medvedev could finally be the player who will break up the dominance of tennis’ big three. Of course, Tsitsipas also looks to be a part of the next wave of tennis stars, and it’s likely that this will be just the first of many ATP Finals clashes between the two.

“Hopefully, we’re going to have a lot of matches to come throughout our careers, in the later stages of the tournament,” Medvedev said, via ATPTour.com. “Hopefully we can have a lot of great matches to come.”

Meanwhile, Nadal (4/9) is hoping to get off to a strong start against defending ATP Finals champion Zverev (7/4). Nadal would usually be a bigger favorite against the young German – he has a 5-0 career record against Zverev – but an abdominal strain suffered during the Paris Masters took him out of that tournament, and even had him questionable for London during the week.

Nadal appears set to play on Monday, which should mean that he is close to 100 percent. If he can win the tournament – or reach the final after an undefeated round-robin campaign – he’ll be able to finish the season as the year-end No. 1 player.

Meanwhile, Zverev is hoping to end a somewhat disappointing season on a high note, with a second consecutive ATP Finals title.

“As everyone probably knows, I didn’t have the best season I wanted to have, but I’m still top eight in the world, and made London,” Zverev said, via ATPTour.com. “A lot of people would dream of that, so being with these guys is an unbelievable honor, and I wanted to come back here and give myself a chance to retain my title.”

Back Against the Wall for Federer

Day 1 of the ATP Finals saw the first upset of the tournament, as Roger Federer fell 7-5, 7-5 to Dominic Thiem. It marked the third time Thiem has beaten Federer this season, and put the 20-time Grand Slam winner on the ropes after just one match.

“It’s a normal tournament from here on forward,” Federer told reporters. “Not allowed to lose anymore for me. That’s how it is every week of the year for the last 20 years, so from that standpoint there is nothing new there.”

Meanwhile, Novak Djokovic had no trouble in his opener vs. Matteo Berrettini, cruising to a 6-2, 6-1 victory to open the ATP Finals. Djokovic is now a 5/6 favorite to win the ATP Finals, while Federer has drifted to 9/1 after his loss.