SCOTLAND’S Cameron Norrie marked his US Open debut with an easy win over Russian Dmitry Tursunov who retired at the start of the third set because of a knee injury with his opponent two sets ahead and cruising.

Johannesburg-born Norrie, from Fort William, won a tight opening set on Court 14 on the tie-break before racing to a 6-1 score in the second when his opponent pulled out.

The first set went with serve until the tie-break which Tursunov, once ranked as high as 20 in the world, led 2-1 after taking the first point against serve.

Norrie bounced back and led 8-7 when he was able to break Tursunov’s serve and claim the tie-break 9-7.

However, the Briton, ranked at 225 and over 400 places higher than his opponent, then dropped his serve in the first game of the second set.

Norrie broke back and then held serve before breaking his opponent in the fourth game to lead 3-1.

After Norrie held to love to lead the set 4-1, Tursunov called for the trainer to get some strapping to his right knee.

Norrie broke Tursunov again before holding to love in game seven for a comfortable 6-1 victory in the second set.

Tursunov, who has never gone beyond the third round at the US Open, then retired to hand his opponent an easy victory and a place in the second round.

Elsewhere, Heather Watson crashed out on the opening day.

The Briton was broken in the opening game on court number four and lost the first set to France’s Alize Cornet despite saving three set points at 3-5.

The 25-year-old twice recovered breaks in the second set but lost serve again at 4-4 before Cornet sealed victory in one hour and 36 minutes.

Her serve let her down, with seven double faults, including four in a row in the second set, while her first-serve percentage was only 47% overall.

Watson has now lost all seven of her main draw singles matches at Flushing Meadows.