Four of the Top 5 seeds will be in action on a busy Monday at the China Open. We preview the must-see matchups right here, courtesy of wtatennis.com contributor Chris Oddo.
First and Second Rounds
 Angelique Kerber (GER #1) vs. Katerina Siniakova (CZE #56)
Head-to-head: Kerber leads, 1-0
Key Stat: Kerber has reached the quarterfinals in three of the last four years at Beijing, but has never reached the semis.
Angelique Kerber is hoping to continue her fantastic season in Beijing with a deep run and that all starts with a first-round matchup with 20 year old Czech Katerina Siniakova. It's been a good summer and fall for Siniakova. She has reached her first two WTA finals and is playing just a sliver shy of her career-high ranking of No.53. Last week she qualified for Wuhan and upset Timea Babos before falling to Caroline Wozniacki in the second round. But facing World No.1 Angelique Kerber in this her career year? That's a different level of challenge for Siniakova, who has only faced two Top 10 opponents in her career to date. Kerber, meanwhile, is just focused on keeping the routine and rhythm that has made her 2016 so successful.
"I'm trying to going to each tournament thinking match by match, not thinking too much what's happen around, just playing my best, practicing good during the tournaments, have good recovery," she said. "Yeah, just go and play good matches."
Pick: Kerber in two
Madison Keys is looking to cash in on a golden opportunity to put some distance between herself and the rest of the pack when it comes to qualification for this year's BNP Paribas WTA Finals Singapore presented by SC Global. Yaroslava Shvedova's upset of Carla Suárez Navarro in first-round action at Beijing means that Keys can stretch her lead over the Spaniard - currently ranked No.9 on the Road to Singapore leaderboard - with each victory she earns this week. On Monday, Keys will face Frenchwoman Kristina Mladenovic in a rematch of last year's first-round battle in Beijing. Keys won that one in straight sets and also defeated Mladenovic at the Olympics in Rio this year, where she won the final four points of a third set tie-break to prevail. Mladenovic, who defeated Jelena Jankovic in three sets on Sunday, has seen her ranking drop outside of the Top 50 for the first time since last spring and has dropped five of her last six against the Top 10.
Pick: Keys in three
Defending champion Garbiñe Muguruza is looking for a late-season push to lock up her second straight WTA Finals appearance, and the 22 year old Spaniard is happy to be back in Beijing, the site of one of her biggest titles to date.
"I think it's very, very satisfying when you go to a tournament where you know you played well, you feel welcome," she said on Saturday after defeating Irina-Camelia Begu in three sets. "But honestly, this was last year. Nobody really is thinking about who won last year. It's all about who is going to win this year, who is winning. I'm not really thinking. I'm just going for my match, just concentrating on the next one."
The next one for Muguruza will come against Kazakhstan's Yulia Putintseva. The fiery 21-year-old notched her first Top 10 win of the season two weeks ago in Tokyo and she'll look to claim another big scalp when she meets Muguruza for the first time on Monday. Muguruza has lost more matches against players ranked outside of the Top 20 than any other player in the Top 5, so she'll have to be dialed in from the get-go to book her spot in the sweet sixteen.
Pick: Muguruza in three
Agnieszka Radwanska has always been a threat to win the title in Beijing, and 2016 is no exception. The Pole owns a 21-7 lifetime record at the China Open and has been to at least the semifinals in four of the last seven years.
"I'm just feeling very well here," Radwanska said after dispatching Chinese wild card Wang Qiang 6-2, 6-2 on Sunday. "I like the courts. I like the conditions. Everything suits me. So just, you know, very happy that I can really play my best tennis here."
Next up for the 2011 Beijing champion will be a meeting with Russia's Ekaterina Makarova. Radwanska cruised past Makarova in second-round action at Wuhan last week to improve her record against the southpaw to 5-1 on hardcourts. Makarova has put up inconsistent results in 2016, but she has earned nine Top 5 wins in her career and is capable of defeating anybody when she's at her best.
Pick: Radwanska in three