Johanna Konta  vs. Naomi Osaka
The day session in Laver opens with an intriguing encounter between one of the WTA’s hottest players, in Konta, and one of its coolest, in Osaka. The Brit is coming off a career year in 2016, and a career week in Sydney, where she beat Agnieszka Radwanska for the title. I thought she might have a letdown against a tricky opponent, Kirsten Flipkens, in her first match in Melbourne, but she kept rolling right along. The 19-year-old Osaka, besides charming tennis hipsters around the world, has shown that she can hit anyone off the court, at least for a few games at a time. Konta won their only meeting, two years ago in U.S. Open qualifying, in straight sets.
Alexander Zverev  vs. Frances Tiafoe
At 19, Zverev is just a year older than Tiafoe, but so far he’s winning their NextGen race by a country mile. The German is ranked No. 24 and has a win over Roger Federer, while the American is at No. 108. But this is a marathon, not a sprint, and Tiafoe is making progress. He survived a three-set scare in qualifying, and his opening-round win over Mikhail Kukushkin was his first in a main draw at a major. These two youngsters have never played, so we don’t know how their topspin-heavy baseline styles will match up; Zverev is the bigger hitter, but Tiafoe is the quicker defender. At 6’6”, Zverev will come in with an obvious advantage on a key shot: The serve.
Rafael Nadal  vs. Marcos Baghdatis
On paper, this looks one-sided. Nadal leads his head-to-head with Baghdatis 8-1, and the Spaniard’s lefty topspin has always been murder on the Cypriot’s vulnerable two-handed backhand. Fortunately for Baghdatis, rather than playing this match on paper, they’ll play it at night in Rod Laver Arena, a place where Melbourne’s raucous Greek chorus has helped him in the past. While this is a difficult match-up for Baghdatis, he did push Rafa to a third set the last time they played, and he’s coming off a decent run to the semis in Auckland. But Nadal has mostly been sharp this year, as well.