Lucy Akers (Palmerston North) and the quirky Cortaflex Tinapai notched the fastest time of the day with 37.71, but dropped a brick in the final fence as they flew towards the finish.
Olympian Daniel Meech (Taupo) and the German import Carlotta, starting in her biggest ever class, went for a steady clear in a deceptively fast time to go clear in 41.59.
Then came the Australians _ Tim Clark and his showy steel grey Caltango took the third to last fence in 40.45 with magazine editor Paula Hamood and her big spooky grey Nero GHP riding a brilliant clear in 41.47.
That left the gates open for the 37-year-old Cameron.
"He's big strong forward going horse and this was ideal for him,'' she said of I Reckon.
"I thought the others probably hadn't gone as quick as they may have - probably because it is the beginning of a big week.''
Cameron has only had the ride since December, but says he had been consistent, placing in all of his last 10 starts.
"The Lady Rider class (on Thursday) is at the top of my wish list for this show, but I'm really happy to win this,'' she said. "It's always exciting to win a major title win here.''
Cameron will start Campione GNZ (owned by the Cameron family and Gary Alton) and I Reckon in the Lady Rider on Thursday afternoon.
She's disappointed not to have her rising little star Lights Out at the show - she's just had her second major colic surgery in nine months.
Cameron has been competing at the Horse of the Year Show since she was about 15 she figures and has won many a title and featured in many a line-up.
A long-time track rider, Cameron's race training partner Gary Alton is facing a tough week without his star rider.
Cameron's win was a special one for her mother Audrey.
"That jump-off was particularly nerve-wracking,'' she said with a chuckle. "It's the first time I didn't bring flowers from the garden for the truck - it must have been a sign.''
The Horse of the Year Show has attracted more than 2600 horses and riders from all over the country. The six day show is expected to attract more than 75,000 spectators to the Hawke's Bay Showgrounds.
The show culminates on Sunday afternoon with the presentation of the Bell Tea Olympic Cup for showjumper of the year.
Results: Norwood Gold Cup: Catherine Cameron (Cambridge) I Reckon (owned by Stephanie Anderson) 1, Paula Hamood (Australia) Nero GHP 2, Daniel Meech (Taupo) Carlotta (owned by the Burnett-Grant family) 3, Samantha McIntosh (Cambridge) Estina 4, Lucy Akers (Palmerston North) Cortaflex Tinapai 5, Tim Clarke (Australia) Caltango 6.
Junior rider: Rebekah van Tiel (Karaka) Leeston Eagle 1, Rebekah van Tiel (Karaka) Double J Angelic 2, Megan Webb (Hunterville) Abernaki Chief 3, Henry Booth (Masterton) Getemshorty 4, Melody Matheson (Hastings) Scottish Lad 5, Lily Tootill (Pukekohe) Ngahiwi Cruise 6.
Seven-year-old: Georgina Power (Christchurch) Brooklynite 1, Katie McVean (Mystery Creek) Dunstan Kiwi Iron Mark 2, Daniel Meech (Taupo) Branson MVNZ 3, Katie McVean (Mystery Creek) Dunstan Springfield 4, Amanda Roy (Clinton) Rumours NZPH 5, Katie McVean (Mystery Creek) Dunstan Delilah 6.
