The German was so dominant in the dressage and cross-country legs that he had a 6.9 point lead heading into the decisive day.

A second fence down would have ended his chances but Jung held firm to repeat his 2015 and 2016 successes at the Kentucky Horse Park in Lexington.

He became the first rider to win the International Equestrian Federation Classics event in three successive years. 

"She is a really wonderful horse, a top fighting girl," said the 34-year-old afterwards. 

"She jumped wonderfully and was only a bit spooky at the white fence. 

"I really like Kentucky - and not just because I win here - but because I feel very welcome. 

"You can train the horse for every phase and it's why I like it and why I come back."

France's Maxime Livio finished in second place on 44.6 points after a clear round on Qalao Des Mers.

Britain's Zara Tindall took third on High Kingdom with 46.6.

It marked the British Royal Family member's best finish at a major competition since the 35-year-old won the World Championships in 2006.

The result continued the superb form Jung showed last year when winning a second successive individual Olympic gold medal on Sam FBW.

He is also now the co-leader in the Classics series after three of six legs.

Jung lies joint top on 27 points with Livio.

Australia's Hazel Shannon lies third on 15 points. 

Classic action will resume on Thursday (May 4) with the Badminton Horse Trials in the English county of Gloucestershire.

Jung was also the winner there last year.