Joint Effort became the third mare to win the race in its 120-year history, joining Raggamuffin Rose (1994) and Flying Spy (1944).
Stalker, a sheep and cattle farmer, races Joint Effort with Auckland breeders Stuart and Sue Murray.
Stalker took a half share in Joint Effort on the suggestion of the Murrays, which led to the naming of the mare.
Stalker's son, Craig, was studying veterinary science at Massey University with the Murrays' son, Fraser.
They worked horses on the Stalker farm during holidays and Mrs Murray thought it would be a good way to train Joint Effort.
The 7yr-old Desert Fox-Erincorp mare won five races on the flat including a 3200m race at Wingatui.
She was switched to hurdling last winter and has won five races from 12 starts in that role.
Joint Effort was educated to hurdling by Paul Richards at Wingatui and won at her second start over fences.
Night Bell, the fourth dam of Joint Effort, left Loch Linnhe, winner of the New Zealand and Australian Grand National Steeplechases in 1974 and the Great Northern and Waikato Steeplechases the following year for Southland owner Bill Hazlett and trainer Bill Hillis.
The previous Southland-trained winner of the National Hurdles was Arch Rival from the Gary Gibson stable in 1999.
Stalker won six races with Cut `N' Dry and he has won races with Final Cut and Tsunami.
Final Cut was put down because of a tendon injury after a win and a third in two starts over hurdles.
Joint Effort gave Cambridge jockey Matthew Cropp (18) his biggest win.
Cropp has a 100% winning record on the mare from four rides.
He is keen for Stalker to take Joint Effort to the Great Northern Hurdles on September 4.
Stalker said he would freshen Joint Effort before making a decision.
Cropp settled Joint Effort in fourth place and headed the leader, Waitaha Toa, at the third-last fence.
Joint Effort won by 22 lengths.
"She struggled over the second last and I had a look behind me and she was a fair way in front and all we had to do was jump the last.
She did that and she just kept going," Cropp said.
Cropp, who works for Cambridge trainer Ralph Manning, said he sought the advice of his former boss, Craig Thornton, a renowned jumps rider.
"He told me to ride her the way I felt was best and to let her go to sleep in the running."
Cropp switched from flat riding after his weight increased.
He had his first win in a hurdles at Matamata two years ago.
Stephen Blair-Edie, the Riverton trainer, had a 100% record at Riccarton yesterday when he won with Ian Charles, Scarlet Fever and Avoid.
Avoid was having her first start for Blair-Edie and her first race for three months.
She was a winner when trained by Michael Pitman.
Scarlet Fever won five races when trained by Pitman.
Jason Laking, who missed his engagements at Riccarton yesterday due to illness, said he would be fit for Saturday.
His rides include Arctic Ace and Villefranche, whom he rode to last-start wins at Oamaru.
Noel Harris is back in New Zealand after a stint in Malaysia.
He has the mount on Vonusti in the Foxbridge Plate at Te Rapa on Saturday.
The Foxton Racing Club has had a meeting scheduled for next Thursday to replace the meeting abandoned on August 5.
The Foxton meeting for August 26 has been transferred to Woodville.
