Unflappable American Brian Harman romped to a six-stroke victory in the British Open as he kept a high-calibre chasing pack at bay on the greatest day of his career at a rain-drenched Royal Liverpool on Sunday.

The 36-year-old PGA Tour stalwart, an avid hunter back home in Georgia, offered hope of a thrilling conclusion to the 151st championship for the soaked galleries with some early jitters.

But the steadfast left-hander proved elusive prey for his bedraggled pursuers as he turned the final day into a procession, calmly plotted his way to a final one-under round of 70 for a 13-under total of 271.

The rest were left battling for second place with Spain's Jon Rahm, Austria's Sepp Straka, South Korea's Tom Kim and Australian Jason Day tied on seven under.

India's Shubhankar Sharma finished tied-eighth. It's the best-ever finish by an Indian golfer at the oldest sporting event in the world. He bettered Jyoti Randhawa's tied-27th in 2004. However, it fell short of Anirban Lahiri's tied-fifth finish 2015 PGA Championship. That remains the best Indian result in a major.

Harman had seized control of the tournament with a sensational second-round 65 on Friday and began Sunday's climax five shots clear of compatriot Cameron Young and six ahead of Rahm who roared into contention with a 63 on Saturday.

Harman's bogey at the second hole and another at the fifth on Sunday after driving into a gorse bush allowed Masters champion Rahm to briefly close within three strokes.

Harman's previous best performance at a major was in the 2017 US Open when he led by one stroke after 54 holes only to be overhauled by fellow American Brooks Koepka.

But this time, he finished the job with his trusty putter again his weapon of choice.

Written with inputs from Reuters