Caroline Wozniacki cameback to defeat former U.S. Open champ Svetlana Kuznetsova ensuring her first slam quarterfinal versus American sensation Melanie Oudin.

It’s not often a player gets more of a challenge from the broadcast booth. But that was precisely the case for Novak Djokovic, who had an easy go of it in a straight sets 6-1, 6-2, 6-3 Round of 16 triumph over No.15 veteran Radek Stepanek.

The same pair met a couple of years ago giving the crowd a lot more drama with Djokovic overcoming cramps to pull out a final set tiebreak en route to the final. But tonight was nothing like that match with the overlooked No.4 Serb having too much for an unsteady Stepanek.

In the lone competitive set, a perfect forehand topspin lob gave Nole a break of serve for 4-3. He managed to save one break point in the next game. Following a Stepanek hold that featured some nifty volleying skills, Djokovic crawled out of Love-30 taking the next four points to advance to a quarterfinal versus 10th seeded Fernando Verdasco, who bounced back from a set down to oust American John Isner in four 4-6, 6-4, 6-4, 6-4.

Isner’s departure was historic because it marked the first time in U.S. Open history that no American male had made the quarterfinals. Pretty sad considering it’s been around since 1881.

At the conclusion of Djokovic’s win, he entertained the same audience he irked last year in a quarter win over Andy Roddick. This time, the chatty Serb while talking to ESPN’s Darren Cahill challenged John McEnroe to come down and hit with him. The hilarious confrontation which included Djokovic impersonating Johnny Mac’s serve and his infamous “You cannot be serious” quote at umpires will surely go down as one of the most classic things to happen at the Open.

Eventually, McEnroe who took off the tie made it down to courtside and did a funny imitation of his own pretending to serve like Djokovic bouncing the ball which got plenty of chuckles. They played three points with the popular four-time winner earning two points with what else but his crafty net skills which still looked pretty good.

“If the moment is right, it comes spontaneously,” Djokovic later said after shaking hands with the idol. “I thought the moment was right. The crowd loved it, and that was the most important thing.“

As for the real stuff, at least the Ashe Stadium capacity crowd got to see one superb match with No.9 Caroline Wozniacki coming back to edge former 2004 champ Svetlana Kuznetsova (6) 2-6, 7-6 (5), 7-6 (3). Playing against the two-time slam winner including this year’s French, the 19 year-old from Denmark showed tremendous poise after getting outplayed in the first set.

Kuznetsova worked her from side to side slugging plenty of winners from all angles. The 24 year-old Russian was the aggressor throughout which might better explain how she wound up with over triple the winners (Kuznetsova-59, Wozniacki-16). But as often is the case when you go for more, the unforced errors can pile up and that’s exactly what happened in the second and third sets where she committed a large part of a match high 63 to her younger opponent’s 25.

Wozniacki’s consistency helped her stay in the match. When asked what turned it around by ESPN’s Brad Gilbert, the Dane indicated that she was more aggressive which didn’t allow Kuznetsova to dictate as much.

After taking the second breaker to level the match, she dropped serve falling behind 0-2 in the final set. But Kuznetsova’s level dropped allowing Wozniacki to claim the next three games. She was firmly in control after breaking for 5-3 but as often happens with an inexperienced player in such a big spot, the lanky teenager couldn’t close out Kuznetsova allowing her to get back on serve.

With the veteran serving to stay in the match, a running winner that finished off a scintillating point gave her match point. However, Kuznetsova showed why she’s won coming up with a deadly backhand winner down the line to erase it before holding. The former hitting pair in Eastbourne this past summer exchanged holds with Kuznetsova saving another match point with an ace to force a deciding breaker.

In it, a Kuznetsova double along with an unforced error handed Wozniacki a 3-0 double mini-break lead. But before you could blink, it was three all thanks to some great points by the Russian who found the angles.

Just when momentum seemed back on her side, she dropped the next point to go down 3-4. This time, Wozniacki won her two service points by playing steady while Kuznetsova misfired setting up three more match points.

With her first quarter berth on the line, she cashed in thanks to some great hustle running down a backhand in the corner to draw a Kuznetsova miss at the net. Pumped up, a smiling Wozniacki threw her hands in the air and tossed the racket before running up to get congrats.

“She’s [Melanie Oudin] had an amazing run. Hopefully someone from the crowd will cheer for me,” cracked Wozniacki of her next opponent to cheers and laughter from Ashe spectators.

Whoever wins their quarter will be favored to make their first ever final with Kateryna Bondarenko and Yanina Wickmayer vying for the other spot in a top half that’s seen higher seeds go by the wayside with Oudin responsible for three Russians (No.4 Elena Dementieva, No.29 Maria Sharapova & No.13 Nadia Petrova).

With her win tonight, Wozniacki eliminated the last remaining Russian in either men’s or women’s draws meaning that for the first time in quite a while, not one player from Russia made the quarters. In fact, every single win by the 17 year-old from Atlanta, Georgia has come at the expense of Russia with her posting her first Open win back in Round One over Anastasia Pavlyuchenkova.

“She’s on a roll. And she has nothing to lose,” pointed out Petrova after letting it slip away. “She goes, enjoys it, crowd is behind her. She’s just having a blast out there.”

“This,” Oudin said, “is what I’ve wanted forever.”