Marin Cilic and Kei Nishikori had two very different paths to the US Open final. And yet, they weren't so different. They both involved an incredible upset in the semifinal. Theyhave both never reached a Grand Slam final before. And, most importantly, no one ever expected either of them to get here.

Nishikori's path these two weeks has certainly been the more arduous one. He was touted as a rising youngster five years ago. He was the next star waiting to break through four years ago. In fact, his game has been more and more impressive ever since Brad Gilbert started working with him around that time.

Unfortunately for Kei, injuries seemed to have cost him everything. It would always be something or other whenever he was ready to make the next step. It would never be anything dramatic that would require missing a significant portion of the season, and yet it always felt like Kei was missing critical tournaments. Until he actually stepped out on court two weeks ago, we weren't even sure that Nishikori would be playing the US Open this year. He missed the two lead-up Masters events with a foot injury, and reports were that it was doubtful he would play in Flushing Meadows.

Even once he was playing, and playing well, it still felt inconceivable that he would reach this final. First, a four-hour match against Milos Raonic was in his way. He completed that at 2:26 AM, but there was no way he could beat Stanislas Wawrinka barely 36 hours after that. A second four-hour match later, and there was no way he could beat Novak Djokovic. Now, after coming through a historic victory, he is searching for his first Grand Slam title.

Marin Cilic's path here may not have been as dramatic, but it was unexpected for entirely different reasons. Cilic reached the Australian Open semifinal in 2010 but could never repeat that performance until now. Then, disaster struck last year with a nine-month ban for testing positive for a performance-enhancing substance. He claimed it was unintentional, and the Court of Arbitration for Sport agreed with him. After the ban was reduced to four months, Cilic was ready to play at the end of the season.

Still, even with the 2010 success, Cilic has flown entirely under everyone's radar. He was always a slight upset threat, but it never dawned on anyone (except maybe those inside his camp) that he could actually win the whole tournament. Now, after a gutsy five-set victory over Gilles Simon and straight-set dominations of Tomas Berdych and Roger Federer, Cilic is also just one win away from his first Grand Slam title.

This is the first major final since the 2005 Australian Open final (between Marat Safin and Lleyton Hewitt) that has not featured either Federer, Rafael Nadal, or Djokovic. To put that in the insane perspective it belongs in, that is exactly two major finals short of being an entire decade of dominance. This will be the first year in which none of those three has won multiple Grand Slams since 2003. This will also be the first year with two different Grand Slam winners aside from that trio since 2003. This is, without question, the Grand Slam final that nobody–not even history itself–expected.