If someone had said that after the first round in Rio, world no. 1 Novak Djokovic, the top-seeded doubles teams of the Williams sisters along with Pierre-Hugues Herbert and Nicolas Mahut would all be eliminated, many would have questioned their sanity.  However, as a result of topsy-turvy happenings, that is exactly what occurred. 

The world no. 1 Djokovic, received no favors when he was forced to meet former U. S. Open champion Juan Martin Del Potro in the first round.  The battle became an instant classic as both players left little in their respective arsenals, but Del Potro dominated with a lethal forehand and did enough from the backhand side to keep Djokovic on his heels throughout much of the match.  The performance left both players in tears afterward but the Argentine was only beginning as he was forced to play 3 matches in less than 24 hours due to scheduling.  And while he was not as fortunate in doubles competition, he took a solid punch from Joao Sousa yet advanced in straight sets in a second-round singles match.  He now appears to be in the driver’s seat for a run to the semifinals, particularly with the exit of Jo-Wilfried Tsonga. An injured Tsonga could not summon his best effort as he fell to Gilles Muller on Monday.  

The only remaining seed left in Del Potro’s quarter is Roberto Bautista-Agut.  The Spaniard defeated Del Potro at the Australian Open in 2014 but the Argentine is one of a handful of players who have had success powering through the court with groundstrokes on the slow hard courts of Rio, which should continue to present difficulties opponents.

Meanwhile, Rafael Nadal showed no ill effects from an injured wrist that had kept him out of play since Roland Garros.  Despite cautioning interested enthusiasts that he would still be on the sidelines due to the injury had it not been for the Rio games, Nadal powered through his opening round match against Federico Delbonis. However, he could be in for a test against veteran Andreas Seppi on Tuesday and in a potential matchup with the typically competitive Gilles Simon down the road.  But the Spaniard along with 8th-seeded David Goffin appear to be the favorites to face off for a spot in the semifinals.

The third quarter looks to be the most competitive portion of the bracket, with four-seeded Kei Nishikori, six-seeded Gael Monfils and ninth-seeded Marin Cilic all alive and well.  The Frenchman has continued his impressive summer rolling through his first two matches, but a battle with former U. S. Open titlist Cilic will be one of the featured encounters in the round-of-16.  The native of Japan has put together an impressive hard court season as well and has strong hopes of medaling.

Meanwhile, the bottom quarter of the draw has only played opening round matches with Andy Murray, David Ferrer, Benoit Paire and Steve Johnson having moved through. The two-seeded Murray was efficient in his first-round win against Viktor Troicki and is the strong favorite to push through to the semifinals.

In the women’s draw, despite not dropping a set thus far, top-seeded Serena Williams was tested in her first two matches by both Daria Gavrilova and Alize Cornet.  The road will not get any easier for the world no. 1 who will face Elina Svitolina next, and with a win, the winner of the Petra Kvitova-Elena Makarova match.  Power tennis will be on display in a match featuring Williams and either of these two competitors.

In the second quarter, Garbine Muguruza has regained some momentum following her post-French Open championship letdown.  But she will need to defeat a player with a contrasting style next, in Monica Puig.  The Puerto Rican advanced behind a strong performance against Anastasia Pavlyuchenkova, another power hitter, and will need a duplicate effort against the Spaniard using quickness and defense to her advantage.  Kirsten Flipkens, who eliminated Venus Williams in a first-round classic, could stand in the way of the winner and a semifinal appearance.

In the third quarter, Agnieszka Radwanska’s first round exit opened the door for American Madison Keys.  The 21-year old will look to continue her success following a win against Kristina Mladenovic in the second round.  In a battle with numerous ebbs and flows, Keys outlasted the Frenchwoman winning the decisive third set in a tiebreak.  The seven seed will need to get by ninth-seeded Carla Suarez Navarro, who eliminated Ana Ivanovic in the first round, to continue her pursuit of a medal.  Daria Kasatkina or Sara Errani will await the winner.

The strongest portion of the women’s draw lies in the fourth quarter where Svetlana Kuznetsova will meet the red-hot Johanna Konta and Sam Stosur will face Australian Open champion Angelique Kerber with the two winners battling for a spot in the semifinals.  After falling behind Eugenie Bouchard, the German impressively stormed past the Canadian to advance on Tuesday.

In the early stages of the Rio Olympics tennis competition, the theme has clearly been to expect the unexpected.  There are a number of players who feel that they can make a run for a medal.  Many have sent a message to the top seeds that they will need to bring their best to pursue any dreams of standing on the medal podium this weekend. Play continues on Wednesday.