Competition just got interesting at the U.S. Open as Andy Roddick, Maria Sharapova, and Dinara Safina have all been eliminated.

Melanie Oudin’s face was flushed from a mix of exertion and excitement and maybe even a bit of bewilderment — “Yes, I DID beat Maria Sharapova!” running through her mind — when she stepped out of the U.S. Open locker room and saw Mom.

Several hours later, on the same court, another unheralded American who has lived in Georgia pulled off another upset of a past U.S. Open champion: 55th-ranked John Isner pounded 38 aces and eliminated No. 5 Andy Roddick 7-6 (3), 6-3, 3-6, 5-7, 7-6 (5) to reach the fourth round at a major tournament for the first time.

Keeping with the day’s theme, No. 1-seeded Dinara Safina exited, too, a 6-4, 2-6, 7-6 (5) loser against 72nd-ranked Petra Kvitova of the Czech Republic. After escaping the first two rounds with poorly played three-set victories, Safina wasted three match points Saturday night and finished with nine double-faults and 39 total unforced errors. Her departure means the Williams sisters are the only members of the top five women left in the field

On the plus side, at least Roddick was ousted by a fellow American. While I wanted to see Roddick take on Nadal in the final, I’m now completely rooting for this Isner character. The Georgia Bulldogs alum has yet to make his mark during his time on the ATP Tour. This looks like his chance.

Oudin’s story is even more exciting. Not only did she eliminate Maria Sharapova, but she upset Elena Dementieva, a two-time Grand Slam finalist and the Beijing Olympics gold medalist, in the second round. For the sake of diversity, I hope she makes it to the finals.