The 2013 tennis season may be winding down, but players continue to jockey for position in the rankings.
Some, like Juan Martin Del Potro and Angelique Kerber, capitalized on late-season surges to qualify for the year-end championships.
Others, like teen sensations Madison Keys and Eugenie Bouchard, are gaining ground and experience.
This list is not about the battle for No. 1. Some of the players listed here are ranked outside of the Top 20. This is about players experiencing late-season success. These players have taken advantage of the post-U.S. Open schedule to end the year on a high note.