NEW YORK – Friday marked the first time Gael Monfils had appeared in a Grand Slam semifinal since the 2008 French Open when he fell in four sets to then-No. 1 seed Roger Federer. This time, Monfils was in the semis against the now-No. 1 Novak Djokovic in hopes of reaching his first career Grand Slam final. Unfortunately for the Frenchman, the top-seeded Serbian had other ideas.

Exploding out of the gate with a fast start, Djokovic was slowed down a bit by Monfils who certainly made things interesting. In the end, though, Djokovic prevailed, pulling away from the Frenchman to win 6-3, 6-2, 3-6, 6-2 to advance to Sunday's final – his second straight final at the US Open.

But this wasn't simply a top-seed predictably winning and advancing. This match was, to say the least, a bizarre one.

In a match that was played in 93-degree weather with 60 percent humidity, it was Monfils who struggled right out of the gate as he committed what felt like a plethora of double faults to give Djokovic the early advantage – something no one wants to give the No. 1 seed. Despite making things interesting in the opening set, Djokovic hung on to win it.

While he looked a bit better in the second set, Monfils continued to be his own worst enemy as he committed a few more double faults and set himself up for some unforced errors, ultimately giving the top-seeded Serbian a two-sets-to-none lead. Djokovic won 14 of 16 first-serve points, needing just 29 minutes to win the second set as Monfils appeared to simply be going through the motions at times.

The start of the third set again was not an auspicious one by Monfils as his underwhelming performance was met with jeers from the crowd. Suddenly, it looked as if the tide had turned with the Frenchman finding his game and Djokovic being a bit rattled. Monfils now had the crowd on his side and, despite some fight from the Serbian, took the third set.

With the humidity still a factor, Djokovic tore his shirt open in a possible effort to regain traction or to expel some frustration. Whatever the case was, it worked.

Monfils looked to pick up where he left off in the third set but it was Djokovic who fought back to take the opening game, causing the Frenchman to double over in either fatigue or frustration.

Djokovic eventually took a 3-2 lead in the fourth set but continued to double fault as it looked like he had cramped up. The trainer came out to treat Djokovic's right shoulder while Monfils had momentarily left the court for a medical timeout.

Whatever issues Djokovic had, he worked through them to take the rest of the set – and the match – to advance to Sunday's final. After one ace and seven double-faults, though, there should be a fair bit of concern surrounding his serve.

When asked to describe the match following his win, Djokovic said, “Humid. I think that’s all we were thinking about and feeling the last couple of sets. Conditions were quite different from most of the days of this tournament. It’s the same for the both of us we kind of expected it.”

Overall, it was a bizarre match between Djokovic and Monfils – one that lasted a grand total of two hours and 32 minutes. The Frenchman, though, was not at his best as he committed a total of 11 double faults in addition to 52 unforced errors, which was almost twice as many as Djokovic's 27. He also left many question marks as to his tactics, motivation, strategy or lack thereof.

Asked about his tactics, Monfils responded, “First question is, like, 'You're not competing?' . Yes, I'm competing,” an agitated Monfils said. “I made a sign to my coach to say, 'OK, I'm going to Plan B.'” He continued, “I had to change. That's a little bit tough, because, for sure, people are not really ready to see that,” Monfils said. “Definitely, I try to get in his head, try to create something new for him to see.”

Djokovic responded afterward, “I thought, at times, that he was maybe behaving a little bit - for some terms and judgments - unacceptable. But I guess that was part of his tactics. If he said that you have to believe him, I guess.”

With the victory, though, Djokovic ties Roger Federer and Jimmy Connors for third in the Open Era with his seventh trip to the US Open final. In fact, on Sunday, he will be eyeing his 13th Grand Slam title, which would put him just one behind Pete Sampras and Rafael Nadal who are tied for second behind the aforementioned Federer.

To say the very least, it was a crazy way to open Friday's semi-final schedule.