Japanese champion Gentildonna has ended her career in triumph, claiming her seventh Group One win in the Arima Kinen.

She is one of five Japanese horses, including her sire Deep Impact, to win seven Group One races on turf and her career earnings of Y1,726,030,400 ($A18.22 million) are second only to T. M. Opera O.

The Arima Kinen is known as the people's race with 10 of the 16 runners each year selected by public vote.

A dual winner of the Japan Cup, Gentildonna made a clean start from gate four on Sunday and settled third behind Verxina and Epiphaneia and made her move rounding the home turn.

At the 100m mark, Gentildonna pulled away to beat To The World by three-quarters of a length.

"I'm really glad she was able to show her best performance in the last race of her career," jockey Keita Tosaki said.

"When I rode her the last time (Tenno Sho), she was easy to ride and very clever, so I felt very comfortable riding her this time.

"I was able to race her just as I had imagined, settling her towards the front and making use of her persistent late charge.

More than 40,000 of the 116,00 strong crowd stayed well after the last race for a special ceremony to mark the mare's retirement.