Jack Sock was finally a rising American star last year, something fans have been needing for a while now. He never had a big breakthrough at a major tournament, but he was consistently winning matches and competing even against better players. His doubles success with Vasek Pospisil seemed to spur him forward and singles as well, culminating in him cracking the top 50 in Bercy last year.

This was supposed to finally be the year where he could put things all together and start challenging players in the top 20 or higher. Expectations were high heading into the Australian Open. But hip surgery in December put off his start to 2015. Well, the start has arrived now and it has arrived in style. Sockhas played three consecutive tough three-set matches, and all of a sudden he is in his first career fourth round at a Masters 1000 tournament. Yen-Hsun Lu and Gilles Muller are no pushovers, although they play radically different styles, but Sock managed to fight his way through those matches, pulling out the latter in a third-set tiebreak.

Sock is clearly not yet quite back up to form after sitting out for a few months. However, his game lends itself to playing his way into form relatively quickly. Following big serves with big forehands is how you get into a rhythm with just a few matches. Still, the fact that he has come back with no match play preparation–no Challenger or even doubles to warm up–and still won three matches against top-100 players is remarkable in its own right.

His match against Roberto Bautista-Agut was impressive. Bautista-Agut has been playing well this year and was in-form here at Indian Wells. It was a high-power match between two strong hitters, and Sock came out ahead at the end. This is clearly the best tournament of his career so far–and it's not over yet.

Of course, what is Sock's reward for all of this? He gets a round of 16 matchup with Roger Federer. It is probably way too much to ask Sock to beat an in-form Federer with so little match preparation. On the other hand, when you want to have a breakthrough tournament for your young career, there isn't a much better way to do it than by beating Federer to get to a quarterfinal.