Day Four action at the Memphis Open presented by ServiceMaster will start Thursday with an all-American match-up between Olympic medalist Steve Johnson, the 4th seed, and qualifier Tim Smyczek. It will be their second meeting, the last coming back in 2013, a win by Johnson.

The tallest man in tennis will follow when top seed Ivo Karlovic takes on Georgian Nikoloz Basilashvili. Twice they have played; both occasions were in 2015 and Karlovic wins. The night session includes Taylor Fritz who won a spectacular match in the previous round from three match points down, versus Australian Matt Ebden who is rebuilding his ranking after injuries forced him off the tour for a lengthy period.

On Grandstand, Darian King of Barbados who advanced through the qualifying rounds and scored an impressive upset over 5th seed Bernard Tomic in the first round will play the tenacious Kazakh Mikhail Kukushkin.

The United States is guaranteed a player in the singles semifinals after second seed John Isner and Donald Young won their matches Wednesday to set up a quarterfinal clash.

Isner, a finalist at the Racquet Club of Memphis in 2010, powered down 26 aces while coming back from a set down to defeat Yoshihito Nishioka of Japan 4-6, 6-3, 6-4. Isner explained that having a first round bye was like a double-edged sword because his opponent had already got in a groove with a match under his belt.

“The main thing is I held my composure pretty good and got an early break in the second and was able to ride it out and the third set was tough,” Isner said. “I really like the conditions – the court is on the slower side and the balls are a bit heavy but I like that.

“The tournament has a different feel to me than most tournaments I play. I don’t even need a car, just walk across the street; essentially my hotel room is my locker room. It’s so nice and convenient here. I love it.”

Young got a bit of his own back against Reilly Opelka. They had played once before at last year’s BB&T Atlanta Open and on that occasion 19-year-old Opelka recorded the win. After a close first set, Young, playing in Memphis for the tenth time, scored his 100th career win 7-6, 6-3.

“It feels good. I’m happy to be here again and put two matches together,” Young said. “Anytime you can win a couple of matches in a row anywhere, particularly in the States, it’s a plus. We need more tournaments like this because we play better here.”

In other results Ryan Harrison continued his impressive form, upsetting 3rd seed and former Memphis Open champion Sam Querrey.

2008 winner and the seventh seed Steve Darcis was defeated by Damir Dzumhur 7-6, 6-4 while Mikhail Kukushkin defeated German Benjamin Becker 6-3, 6-4. Becker came into the main draw as a “lucky loser” after his countryman Dustin Brown had to withdraw from the tournament with a back issue he first sustained while playing last week in Montpellier, France. Basilishvili swept past Aussie Jordan Thompson 6-3, 6-0.