The other fancied contenders in the eighteen runner field included Lily Noble, Mau Lea, Social Club, Cordierite, Tosen Bliss and Sayakachan.
Entering the straight the leaders began to fade and Lily Noble went to the front but Lucky Lilac produced a sustained run on the outside, gained the advantage in the last 200 metres and won by three quarters of a length with Mau Lea taking third place.
After racing in second place behind Maltese Apogee she took the lead in the straight and opened up a clear advantage but was caught on the line and beaten a neck by the five-year-old Win Bright.
[16] In April the filly started odds-on favourite for the Hanshin Himba Stakes and came home eighth in a blanket finish, beaten less than two lengths by the winner Mikki Charm.
She tracked the front-running Aerolithe before launching a strong challenge on the outside but in another close finish she was beaten into fourth place behind Normcore, Primo Scene and Crocosmia.
Lucky Lilac returned from her summer break to contest the Grade 2 Fuchu Himba Stakes over 1800 metres at Tokyo on 14 October and finished third behind Scarlet Color and Frontier Queen.
Christophe Soumillon took over from Ishibashi for the filly's next race, the Grade 1 Queen Elizabeth II Cup on 10 November at Kyoto in which she started the 4.4/1 third choice in the betting behind the three-year-olds Loves Only You and Chrono Genesis.
The pace was not very fast so I thought it would be a little bit hard to make up ground, but finally I took the option to stay in the inside and she really quickened well and at the 200-meter marker when I saw the gap was still open".
[17] On her final appearance of the year Lucky Lilac was sent to Sha Tin Racecourse for the Hong Kong Vase over 2400 metres in December.
With Soumillon again in the saddle she produced a strong late run from the rear of the field to finish second of the fourteen runners behind her fellow Japanese challenger Glory Vase.
She began her fourth campaign on 1 March when she started the 2/1 second favourite for the Nakayama Kinen and finished second behind the four-year-old colt Danon Kingly, beaten one and three quarter lengths by the winner.
By the time the mare made her next appearance, in the Grade 1 Osaka Hai over 2000 metres at Hanshin on 5 April, horse races in Japan were being run behind closed doors owing to the COVID-19 pandemic.
She settled in third place on the inside as Danon Kingly set the from Jinambo but looked to be short of racing room as the field entered the straight.
She made good progress on the outside approaching the final turn, went to the front 300 metres from the finish and kept on well to win by a neck from Salacia, with Loves Only You the same distance back in third..
Breaking smoothly from the outermost draw, Lucky Lilac settled in mid-division behind Loves Only You, around 12th from the front, edged forward toward the end of the backstretch and continued to advance turning the corners wide.
"[21] On 27 December Lucky Lilac started the 7.1/1 fourth favourite for the Arima Kinen at Nakayama after finishing second to Chrono Genesis in the poll to select the runners.