[1] In 2006, Sunline was an inaugural inductee into the New Zealand Racing Hall of Fame, along with Carbine, Gloaming, Kindergarten, and Phar Lap.
She won first up but was narrowly beaten for the first time by Rose O'War, second-up, in Melbourne's Angus Armanasco Stakes, her 9th career start.
A fortnight later, Sunline was again a favourite in the Queen Elizabeth Stakes (2,000 metres), and led the field over the rise (near the top of the straight), then faded to finished second-last of the six runners.
First up, she scored a win over the multiple Group One winner Tie the Knot in the Warwick Stakes and was installed ante-post favourite for the $3 million W. S. Cox Plate at Moonee Valley.
At her next two starts, Stephen and Trevor McKee then tried to get the mare settle in her races,[citation needed] but she was narrowly defeated in the Theo Marks Quality (by Adam) and the George Main Stakes (by Shogun Lodge).
Leading before the home turn, Sunline held off a late challenge from Tie the Knot, with Caulfield Cup winner Sky Heights in third place.
She then carried the maximum topweight (60 kilograms) to win the first of two Coolmore Classics - at the time, Australia's only Group One race for fillies and mares (three years and over).
Meeting again a week later, in the All-Aged Stakes, Sunline relished the return to weight for age conditions - accounting for Georgie Boy, with Over in third place, to make it three wins from four starts this campaign.
Sunline started her five-year-old campaign in Melbourne, against the sprinters - streaking away in the Manikato Stakes (1,200 metres) at Moonee Valley.
[11] On the last Saturday of October, Sunline took control in the rain-affected going to win the Cox Plate by seven lengths from Caulfield Cup winner Diatribe, with Referral in third place.
[12] Perhaps unsuited in the conditions, fancied runners Tie the Knot (2nd in 1999), Sky Heights (3rd in 1999), and Shogun Lodge (conqueror of Sunline in the George Main Stakes) were beaten a combined margin of more than 100 lengths.
[13] Returning to New Zealand after the Cox Plate, the mare's owners revealed that Sunline had been part of a bidding war from five different countries, including the powerful Godolphin stables in the United Arab Emirates.
In Hong Kong, she led all the way to win the International Mile (1,600 metres),[14] narrowly holding off local icon Fairy King Prawn, with five lengths back to Adam in third place.
In early February, Sunline recorded her eighth win in New Zealand when she was too good for seven other Group One winners in the Waikato Sprint.
The victory kept alive Sunline's wonderful record in her home country, which at career end would stand at 11 wins from as many starts.
For the second year in a row, the race was run on a rain-affected track, and Sunline accounted for Celestial Choir, with Tie the Knot unplaced.
Starting a hot favourite, Sunline was narrowly defeated by El Mirada and Final Fantasy, and then given time off from racing.
All three protests were eventually dismissed on twin grounds that stewards were unable to determine which riders were at fault or satisfy themselves that the interference had affected the result.
[16] She then won the Coolmore Classic for a second time - again carrying the race's maximum handicap of 60 kilograms - and became the first horse in Australasia to win A$9 million in prize money.