He keeps on delivering the pleasant surprises, with the latest at Oamaru yesterday.
The 11yr-old trotter rewarded Graham's perseverance with a win in the feature trot - on Graham's 74th birthday.
The Charing Cross trainer has stuck by the son of Armbro Invasion, even though the gelding had been unable to find the line first since October 2013 - 26 starts before yesterday's win.
To be fair to Quality Invasion, he has toiled away well in the grades, and even finished a close third in the 2013 group 1 New Zealand Free-for-All behind Peak and The Fiery Ginga.
After 26 misses, Quality Invasion had dropped back to the c5 grade, meaning he was just 30m behind seven c2 trotters and 20m behind two c3 trotters.
''The handicaps helped him a lot,'' Graham said.
''We've got him back - that's the main thing. He's had old-age niggles mainly. He's 11 now and he didn't start racing until he was 5 or 6.''
Quality Invasion has packed 82 starts into 5 seasons of racing, and has provided Graham, who owns the horse, with plenty of thrills and more than $160,000 in stake money.
''He's been placed in group races but he's not quite been lucky enough. We've struck some good ones over the years.''
Quality Invasion has an excellent record on grass, winning seven of his 17 starts on the surface.
Sarah Palin has done a similarly tidy job for her owners, although she was doing her bit for her family yesterday.
The Pegasus Spur mare, who has now won five of her 73 starts, joined siblings Father Christmas and Monty Python as winners this week.
