History beckons for Bryans
American twins Bob and Mike Bryan are two victories away from claiming a calendar Grand Slam in mens doubles.
The 35-year-old brothers booked their spot in the semi-finals of the US Open at Flushing Meadows with a straight sets triumph over British duo Colin Fleming and Jonathan Marray.
The Bryans, who have already wrapped up titles in Australia, France and
Wimbledon, won 7-6 (9-7) 6-4.
However, they had to save a brace of set points in the tie-break, the first of these after a mammoth 21-shot rally.
And if the Bryans go on to lift the American crown in New York, they will be the first pair in 62 years to win all four Grand Slam titles in the same year.
Marray, a surprise doubles champion at Wimbledon in 2012, had never even practised before on the Arthur Ashe Court which seats more than 22,500 spectators.
A disappointed Fleming said: "I don't think anyone could have argued with us winning the first set.
"I missed a really easy volley to break at five-all. It's going to be tough to sleep without thinking about that volley.
"I think it was a really high-level match and we can be proud of the way we played but when it came down to it they just produced the goods on the points that mattered.
"That's maybe experience of being in these situations more often. Once we get over the defeat, it's a great memory playing out there in such an amazing match, but it's tough at the moment."
The Bryans took the tie-break on their sixth set point before securing the second and the match after breaking Fleming in the seventh game.
The only other mens doubles Grand Slam was achieved by Aussies Ken McGregor and Frank Sedgman in 1951.