The luck of the Irish was all bad at the US Open as the second representative from the Emerald Isle was forced to retire during his first-round match at Flushing Meadows on Wednesday.
Williams began her bid for a fourth championship at Flushing Meadows and 14th Grand Slam title overall with a 6-1, 6-1 victory over 54th-ranked Bojana Jovanovski of Serbia on Tuesday night.
Rafael Nadal's first match as defending US Open champion was hardly a tour de force, with the Spaniard lucky to record a victory over the relatively lowly-ranked Andrey Golubev on Tuesday.
The last of the reigning women's grand slam champions was shown the door at the U.S. Open Tuesday when French Open winner Li Na succumbed to unseeded Romanian teenager Simona Halep 6-2 7-5.
The Williams sisters have no intentions of quitting anytime soon. If they have their way, they will be around for a lot longer yet, perhaps adding records for longevity to their records on the court.
Five-time champion Roger Federer and Venus Williams advanced into second round at the US Open, while newly-crowned Wimbledon champion Petra Kvitova suffered first round exit on Monday.
Serena Williams will make her long-awaited return to the Arthur Ashe center court today when she opens her latest US Open campaign against Bojana Jovanovski.
Former champion Maria Sharapova survived a first-round scare before roaring back to beat talented British teenager Heather Watson 3-6 7-5 6-3 at the US Open on Monday.
Novak Djokovic faces the daunting prospect of possibly having to beat Roger Federer and Rafa Nadal to win the US Open for the first time and end the year as the world number one.