Her dam Poetry, a half-sister to the St Leger winner Ossian,[3] was bred by the Duke of Devonshire and bought by the Prince of Wales for 430 guineas.

Ridden by John Watts, Thais took the lead a furlong out and won an "exciting race"[8] by a neck from Santa Maura, with Jolly Boat three quarters of a length away in third place.

[9] As Thais and Santa Maura were racing on opposite sides of the wide course the finish was difficult to judge and many observers believed that the latter had won.

With Watts again in the saddle she looked the likely winner in the straight but was overtaken in the last quarter mile and was beaten two lengths into second place by Lord Derby's Canterbury Pilgrim.

[11] In the Coronation Stakes over one mile at Royal Ascot later that month Thais finished in front of Canterbury Pilgrim but was beaten into second place by the Duke of Westminster's Helm, to whom she was conceding seven pounds.