By Tony Jimenez
ST ANDREWS, Scotland, July 20 (Reuters) - Amateur Oliver Schniederjans produced a barrage of birdies to make an early run at the overnight leaders in the final round of the 144th British Open on Monday.
Taking full advantage of calm conditions at St Andrews, the American blitzed his way to 10 under par with a stunning sequence of seven birdies in the opening 10 holes.
Schniederjans is now within two strokes of fellow amateur Paul Dunne, Australian Jason Day and South African Louis Oosthuizen who share the lead on 12 under and will tee-off later in the day.
The 22-year-old Texan qualified for golf's oldest major by winning the Mark McCormack Medal as the world's leading amateur last year.
Schniederjans plans to turn professional at the conclusion of the Open.
Britain's Andy Sullivan and five-times major winner Phil Mickelson were also making excellent progress early in the final round.
Sullivan reeled off four birdies in the first four holes to dash to nine under for the championship while American left-hander Mickelson was on eight under after making inroads on par at the first, sixth, seventh and 10th.
South African Branden Grace leads in the clubhouse on seven-under 281 after firing a six-birdie 67. (Editing by Amlan Chakraborty)