Each quarterfinal at the Masters 1000 tournament in Shanghai features a clear favorite and a clear underdog.  Will form prevail, or does a surprise lie ahead?

Jo-Wilfried Tsonga vs. Florian Mayer

Surprise quarterfinalist Mayer took out David Ferrer in straight sets in the third round, while the seventh-seeded Tsonga dispatched Japan’s Kei Nishikori in straight sets as well.

The Frenchman leads their head to head 3-0. The two most recently met several weeks ago in the semifinals of the ATP 250 event in Metz. Mayer looked primed to pull off the upset after grabbing the opening set, but Tsonga came back to win in his first event after recovering from a knee injury.

Mayer’s impressive performance this week in Shanghai comes after having lost in the opening round of Beijing last week to Richard Gasquet. Tsonga also had a lackluster week in Tokyo, falling to Ivan Dodig in the second round in straight sets.

The implications for this match are far bigger for Tsonga than for Mayer. The Frenchman has quarterfinal points to defend from last year and stands 315 points away from the eighth qualifying spot for the ATP World Tour Finals. A win against Mayer would allow Tsonga to cut that deficit by a substantial amount.

This is definitely Tsonga’s match to lose. The Frenchman’s arsenal of offensive weapons and sheer firepower should pay great dividends on the swift Shanghai courts. He should have plenty of chances to take advantage of the German’s elongated forehand and insufficient movement.

Mayer is known as an unpredictable yet crafty player, who must throw all of the tricks in his bag at Tsonga. In addition, expect Mayer to hone in on the Tsonga backhand, the Frenchman’s main weakness.

Prediction: Tsonga in two sets                                   

Juan Martin Del Potro vs. Nicolas Almagro

In a rematch of a semifinal from last week’s ATP 500 event in Tokyo, Nicolas Almagro will be looking to flip the script when he faces world No. 5 Juan Martin Del Potro. Last week marked the first meeting between the two, which Del Potro won in two tiebreak sets.

The Argentine was afforded the luxury of not having to step on court for his third-round match as a result of Tommy Haas’s withdrawal due to a back injury. Del Potro was apparently dealing with symptoms of a fever in the second round, a match that he barely squeaked out from Philipp Kohlschreiber in a third-set tiebreak. He has still not qualified for the World Tour Finals, but he looks to be in good shape and could use some add points this week to cushion himself.

Almagro reached the quarterfinals after defeating a longtime nemesis in Tomas Berdych. The Spaniard rallied from a set down and was able to overcome the Czech in a third-set tiebreak despite being broken when he served for the match.

Almagro’s run this week and his semifinal run in Tokyo last week should serve as a breath of fresh air considering he failed to win a match in Montreal, Cincinnati, the US Open, and Kuala Lumpur.

The strategy for Almagro is blatantly obvious: avoid the Delpo forehand. Del Potro tends to not to hit out nearly as much on his backhand and sticks to consistent cross-court patterns. It will be vital for Almagro to pin him in the backhand corner and provide himself with as many opportunities as possible to run around his own backhand and dictate with his forehand.

Both guys have massive serves, so breaks will come few and far between, as we saw last week. If Almagro can play the big points well and rise to the occasion in key moments, he should have a working chance in this match.

Prediction: Almagro in three sets

Novak Djokovic vs. Gael Monfils

In a match that pits two of the most elastically inclined, flexible tennis players in the world, Gael Monfils will seek to pull off the massive upset over Djokovic after having just beaten Roger Federer in three sets Thursday.

Djokovic has been in fine form the last two weeks with the highlight being a straight-sets victory over Rafael Nadal in the Beijing finals.  By contrast, Monfils had not had a spectacular fall, but he did produce a semifinal appearance in Winston-Salem before testing John Isner in the second round of the US Open.

The last meeting between these two in Cincinnati in 2011, when Djokovic won in three sets. Monfils has failed to win a match against the Serb in all eight of their previous meetings.

Djokovic is the heavy favorite in this match, but one never knows what to expect from Monfils. To trouble Djokovic, he will have to do many things right. Against the best returner in the world, the Frenchman can take pressure off himself by serving aggressively and maximizing the power behind that shot. In addition, Monfils cannot afford to bring a defensive game plan. The Frenchman can run and defend all day, but that will not win him two sets against Djokovic.

Prediction: Djokovic in three sets

Stanislas Wawrinka vs. Rafael Nadal

Wawrinka comes into this quarterfinal matchup with an 0-10 record against Nadal. As good as the Swiss star’s one-handed backhand is, it has been a helpless victim of the Spaniard’s topspin forehand. (Sound familiar? Yes, this is Wawrinka and not someone else from Switzerland.)

Wawrinka took out two extremely formidable big men, Kevin Anderson and Milos Raonic, on his way to the quarterfinals. The first of those wins came in a third-set tiebreak, a common them in Shanghai this week.  Nadal’s road has been significantly easier as he defeated Alexandr Dolgopolov and Carlos Berlocq in straight sets.

Last week in Beijing, Wawrinka was upset by Sam Querrey and Nadal finished runner-up to Djokovic. Wawrinka stands 7th in the Race for the World Tour Finals in London and would surely love to make an even deeper push in Shanghai to bolster his chances of qualifying.

Nadal will stick to the expected patterns that work to break down the Wawrinka backhand. The Swiss No. 2 will hope for cooler conditions that would help to reduce the effectiveness of Nadal’s topspin. Wawrinka also should try to reach the net as much as possible and try to end points as quickly as possible. That tactic likely will not work over the course of an entire match, despite the fast surface, but the 0-10 record shows how few options he has in this matchup.

Prediction: Nadal in two sets