[3] She was, however, a descendant of the broodmare Lady of Aran, making her a distant relative of many major winners including Teenoso, Sir Percy and Rule of Law.
As at Goodwood, he led from the start and looked likely to win easily when he faltered on a patch of soft ground a furlong out and was beaten a neck by St Louisan.
He made his first appearance of the year in the Field Marshal Stakes over five furlongs at Haydock Park in April and won by two lengths from the gelding Blue Star.
Starting at odds of 11/2,[7] he led for most of the way and accelerated in the closing stages to win by one and a half lengths from the Portland Handicap winner Supreme Gift, with Noble Mark (Phoenix Stakes) in third and Bitty Girl in fifth.
It was intended that Bay Express would be moved up in distance to contest the July Cup but he missed the race after he sustained an injury in his stall.
The colt then ran in the Palace House Stakes at Newmarket and looked the likely winner before he was caught in the final strides and was beaten a neck by the Irish-trained three-year-old Hot Spark.
At York in August, Bay Express started at odds of 100/30[7] for the Nunthorpe Stakes in which his opponents included Hot Spark, Auction Ring and Roman Warrior, and in which he was ridden for the first time by the Scottish jockey Willie Carson.
[8] There was no International Classification of European two-year-olds in 1973: the official handicappers of Britain, Ireland and France compiled separate rankings for horses which competed in those countries.
In the British Free Handicap for three-year-olds he was rated the seventh-best colt of his generation behind Take A Reef, Bustino, Nonoalco, Snow Knight, Giacometti and Saritamer.