2011: two-year-old season

Gentildonna began her career by finishing second in a newcomers race but then won a maiden race to finish the season.

2012: three-year-old season

Gentildonna began her three-year-old season by winning the Grade 3 Shinzan Kinen against male horses over one mile at Kyoto in January and then finished fourth to Hana's Goal in the Tulip Sho at Hanshin Racecourse in March.

On 8 April, Gentildonna contested the first leg of the Fillies' Triple Crown, the Oka Sho over one mile at Hanshin. Starting at odds of 3.9/1, she won by half a length from Verxina.^[1] Gentildonna and Verxina met again in the Yushun Himba (the Japanese Oaks) on 20 May at Tokyo Racecourse. As Gentildonna's regular jockey Yasunari Iwata was on a 4-day suspension in NHK Mile Cup he was replaced by Yuga Kawada. Verxina was preferred in the betting, But Gentildonna won by five lengths to claim the second leg of the Triple Crown.^[2]

After a break of almost four months, Gentildonna returned to contest the Rose Stakes at Hanshin and won by one and a half lengths from Verxina. At Kyoto on 14 October, Gentildonna completed the Triple Crown and defeated Verxina for the fourth time in a row when prevailing by a nose in the Shuka Sho.^[3] She is the fourth Japanese Triple Crown winner after Apapane in 2010. On 24 November, Gentildonna faced an international field in the Japan Cup a race which had never been won by a three-year-old filly. Her rivals included the 2011 Japanese Horse of the Year Orfevre and the Prix de l'Arc de Triomphe winner Solemia. Ridden by Yasunari Iwata and despite coming from a very wide barrier draw of 15, Gentildonna won by a nose form Orfevre. There was a protest made for interference by the connections of Orfevre, and Gentildonna had to wait 20 long minutes until her triumph was confirmed, at the cost of subsequent 2-day suspension to Iwata.^[4]

2013: four-year-old season

On 30 March Gentildonna raced outside Japan for the first time when she started the 11/8 favourite for the Dubai Sheema Classic but was beaten two and a quarter lengths by the Irish six-year-old St Nicholas Abbey. After the race, Yasunari Iwata admitted that St Nicholas Abbey had been the better horse on the night, but pointed out that the filly had been forced to race wide for much of the race.^[5] Gentildonna was off the course for almost three months before returning in the Takarazuka Kinen at Hanshin Racecourse. She started the 7/5 favourite, but finished third of the eleven runners behind Gold Ship and the five-year-old Danon Ballade.

Gentildonna began her autumn campaign in the Tennō Shō at Tokyo on 27 October. She started the even money favourite, but finished second, beaten four lengths by the four-year-old colt Just A Way. After three consecutive defeats, Yasunari Iwata lost the ride on Gentildonna, and when the filly appeared to defend the Japan Cup on 24 November, she was ridden by the British jockey Ryan Moore who had received a temporary contract from the JRA. In front of a crowd of 89,719, Gentildonna started the 11/10 favourite ahead of Gold Ship on 2.4/1 and Eishin Flash on 3.9/1. The race was run at a slow pace, and Moore positioned Gentildonna just behind the leaders before accelerating through a gap on the inside to take the lead in the straight. In the closing stages the three-year-old filly Denim And Ruby produced a strong run on the wide outside, but Gentildonna held on to win by a nose, becoming the first horse to win the race twice. Commenting on her earlier run of defeats Ishizaka said "I had been training her to win every time, but I was very relieved that she was able to claim the Cup again in her last start of the season. Thinking about our staff; they've put in so much effort. The fans still believed in her. I was much relieved that she was able to prove she's still a very special horse".^[6]

2014: five-year-old season

Gentildonna began her 2014 season in the Group Two Kyoto Kinen on 16 February. She started the odds-on favourite but finished sixth of the twelve runners behind the 33/1 outsider Desperado. As in the previous season, Gentildonna was sent to Dubai to contest the Dubai Sheema Classic on 29 March. Ridden by Ryan Moore, she started the 4/1 second favourite behind the Breeders' Cup Turf winner Magician. The mare was restrained in the early stages before making progress with three furlongs to run but was blocked when challenging for the lead in the straight forcing Moore to switch sharply to the right in the closing stages. Gentildonna took the lead from Cirrus des Aigles a furlong from the finish and won "comfortably" by one and a half lengths.^[7] Moore said "I was just hemmed in a bit in the straight. But when I pulled her out she has quickened up very well. She has got an awful lot of heart".^[8] On her return to Japan, the mare again contested the Takarazuka Kinen at Hanshin Racecourse but finished seventh of the twelve runners, seven and a half lengths behind the winner Gold Ship.

After a four-month summer break, Gentildonna returned to contest Japan's three most important autumn races, beginning with the Tenno Sho on 2 November. Ridden for the first time by Keita Tosaki she finished second of the eighteen runners, beaten three quarters of a length Spielberg with the favourite Isla Bonita taking third ahead of the unusually named Love Is Boo Shet. On 3 November she started favourite against seventeen opponents as she attempted to win the Japan Cup for and unprecedented third time. Ridden again by Moore she finished fourth behind Epiphaneia, Just A Way and Spielberg. The Arima Kinen over 2500 metres at Nakayama Racecourse on 28 December attracted its customary strong field, and Gentildonna started fourth in the betting behind Gold Ship, Epiphaneia and Just A Way with the other contenders including Denim And Ruby, One And Only (Tokyo Yushun), Meisho Mambo, Fenomeno and Verxina. Verxina was the early leader before Epiphaneia took the lead 400 metres from the finish but Gentildonna made steady progress in the straight and made her bid for victory in the last 200 metres. She gained the advantage and held off several late challenges to win by three quarters of a length from the three-year-old colt To The World, with Gold Ship, Just A Way, Epiphaneia, Lachesis and Last Impact close behind.

Gentildonna's retirement ceremony was held at Nakayama Racecourse right after she had won the Arima Kinen.^[9]