Dobbs bought the 5yr-old Pins-You Dreamer gelding in August when he was on holiday at Pukekohe.
"I was offered the horse by my niece," Dobbs said.
Ya Dreamin Jonesy had recorded two minor placings in 10 starts for his niece, Julie Hillis, when trained by her husband, Paul.
Ya Dreamin Jonesy cleared maiden ranks at Reefton on January 5 at his fourth start for Dobbs.
The gelding won at Riccarton and Wingatui leading up to his win on Saturday.
"He is the only the second one I have owned," Dobbs said.
The other was Boston Boy, who won 11 races in the 1990s. Dobbs had not raced a horse at Invercargill since 1997 when Boston Boy ran second to Khadeelah, beaten a neck in the Invercargill Cup.
The win on Saturday was the biggest in racing for Dobbs, who rode in jumps and highweight races.
His best win as a rider was the 1968 Otago Steeplechase on Arctic Wind.
Dobbs had an unusual experience as a jumps rider when he swapped mounts during the Lawford Steeplechase at Riccarton in July, 1969.
The incident occurred after a melee halfway through the race at Cutt's Brush, the biggest fence on the course.
Dobbs went into the fence riding Bandarshar and emerged on Lonvato.
Seven of the 11 horses in the field either fell or were brought down.
"Bandarshar was going down just as Lonvato was getting to his feet after falling and before I knew it, I was on Lonvato," Dobbs recalled.
He then pulled up when he realised he was on the wrong horse.
The race was won by Lord Aurora, ridden by B Waerea, who was having his first ride over Riccarton fences.
• Ryan Bishop was suspended for five weeks for careless riding after his win on Champagne Needed in the Southland Guineas at Invercargill on Saturday.
Bishop admitted shifting in after 200m, causing a severe check to Au Naturel, Milo and The Glitzy One.
Champagne Needed had started from the outside in a 14-horse field then led and won decisively.
Bishop is suspended from next Saturday until April 1 inclusive.
The favourite, Milo, raced handy then battled to finish sixth.
His trainer, Michael Pitman, told stewards that Milo had been galloped on and sustained an injury to his left front tendon.
Champagne Needed, who finished fourth, five lengths from Milo in the Dunedin Guineas, was at odds of 51 to one.
He is trained at Riccarton by Shane Kennedy, who races him with his wife, Sandy, Brian and Mary Vieceli, and Louis and Linda Vieceli.
The No Excuse Needed-Bellesinga colt was a $27,000 purchase at the 2009 select sale at Karaka.
Be Ready, a 4yr-old half-sister to Milo, won a maiden race at Wairoa yesterday. She is by My Halo.
• Showcause is finally learning to take racing within his stride, NZPA reports.
The 5yr-old gelding won the $100,000 Avondale Gold Cup (2400m) at Ellerslie on Saturday without protection to his hocks.
His long limbs meant he needed the hock protection as he used to "knock the living hell out of them", his Cambridge trainer, Frank Ritchie, said.
"It's been a lack of maturity that he wasn't able to handle his own action [of stride]," Ritchie said.
"But now he is managing his own manner of moving. He is a light-boned, long-limbed horse who has taken a long time to learn how to gallop effectively."
Showcause has also developed into a top-class stayer.
He has also won the group three $225,000 New Zealand Cup (3200m) at Riccarton in November and the gr two $100,000 City of Auckland Cup (2400m) at Ellerslie on January 1.
He will not race again before the $1 million Auckland Cup (3200m) at Ellerslie on March 9.
He has 53kg and is not liable to a re-handicap.
"He's now as good as he's ever been," Ritchie said.
"I just have to hold him there until the Auckland Cup."
• Jason and Alysha Collett and Harry Kasim were suspended for careless riding at Ellerslie. Jason Collett was also fined $500 after he admitted shifting in at the 200m in the Avondale Guineas when riding Jetset Lad.
He caused checks to Banchee and O'Reilly's Prize.
He is suspended from next Sunday until March 2 inclusive.
Kasim, the rider of Fig Jam (race 1), admitted shifting in at the 1400m, crowding Alegrio and One For The Money.
He is out from Thursday until March 2 inclusive.
Alysha Collett admitted allowing her mount Steflyndo to shift in at the at the 1800m in race 8.
She crowded Dolmabache, Magic Potion and C'est Magnifique.
She is suspended until midnight on Sunday.
Masa Tanaka has been stood down from riding for three weeks after being concussed in a fall at the Awapuni meeting on February 12.
