By Chris Oddo | Tuesday March 15, 2016

It was not a simple straight-sets win for Novak Djokovic, but it was less complicated than his first match here at the BNP Paribas Open, and it was played against stiffer competition, so all signs point to an even better performance in the round of 16 when the Serb meets Feliciano Lopez for the 9th time.

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On Tuesday, Djokovic improved to 8-1 versus Philipp Kohlschreiber with a 7-5, 7-5 victory that featured late hiccups in both sets but also some of the solid tennis that we’ve come to expect from the World No. 1.

Djokokovic hit 16 winners against 23 unforced errors, and saved two of the break points he faced. But he was delayed in his quest to seal Kohlschreiber’s tomb without much fuss, and instead ended up having to scramble to win in straight sets. Though pleased with his play, the Serb was unhappy with his lack of focus.

“I felt better on the court than I did in the first round, which comforts me obviously,” Djokovic said. “But, again, you know, I allowed myself twice to lose the serve when I was break up in both sets. Especially in the second, 40-Love smash, easy backhand, match points, got him back.”

Djokovic, who failed to serve out the match after leading 5-4, 40-0 in the second set, admitted that he was fortunate to win in straight sets, and eagerly looks forward to having a chance at redemption when he meets Lopez tomorrow afternoon.

“Probably still finding right tuning on the court both mentally and physically,” Djokovic said. “But, you know, it's getting better. Hopefully tomorrow it's gonna be even better.”

Lopez came through a tough one against his compatriot Roberto Bautista-Agut, 7-6(5), 6-7(10), 6-4, to reach the fourth round for the second straight year.

In other action on a busy Tuesday, Dominic Thiem downed American Jack Sock, 7-5, 6-7(5), 6-1, to set up a fourth-round matchup with Jo-Wilfried Tsonga. Tsonga took out American Sam Querrey in straight sets.

John Isner was the only American of four in action on Tuesday to reach the quarterfinals. He defeated France’s Adrian Mannarino, 6-4, 7-6(4).

Isner dropped just four points on serve against the Frenchman, but he wasn’t overly thrilled about it. “Everyone knows I can do that,” the No. 9 seed said. “It's the other areas of my game I need to shore up. The first set, you know, I played pretty well. Second set I just kind of went on walkabout a bit. Relied on my serve of course a lot in the second set. I was able to get through, but going forward I think I need to get a little bit better.”

Isner will face Kei Nishikori, who defeated American Steve Johnson, next. Alexander Zverev, the youngest man left in the draw, upset Gilles Simon to set up a fourth-round encounter with Rafael Nadal on Wednesday.

“Going to be a very tough match tomorrow for me, and I have to be ready to fight, to suffer, and to try to play aggressive,” Nadal said of the impending clash with one of the game’s rising stars. “That's what I gonna try, no?”