The Jamie Richards-trained six-year-old was touted as one of the major prospects in an even field, starting the $8.30 fourth favourite after opening her spring campaign with an eye-catching late run for sixth behind Callsign Mav in the Gr.1 Tarzino Trophy (1400m) last month.
After a disappointing second-up effort where she bombed the start over 1600m at Te Rapa, Johnson made sure that didn't happen again as she bounced the daughter of Savabeel away nicely from barrier six, settling one out in midfield in the keenly contested early running.
Johnson had Savy Yong Blonk travelling nicely approaching the home bend and made her move to loom into contention on the back of stablemate Prise De Fer with 400m to run.
Angled the widest in the home straight, Savy Yong Blonk produced a sustained burst of speed to drive hard after Harlech, who swept to the lead inside the final furlong, heading her fellow Matamata raider in the final few bounds to capture a valuable elite-level win.
Harlech fought bravely for second with Prise De Fer battling on strongly for third ahead of Cheval Prometteur.
"It has always been the plan to head to this race, but it does dent the confidence a wee bit off the back of a below par performance that she put in at Te Rapa," Richards said.
"You just have to take her on trust to get away from the gates cleanly, which she did today and Danielle gave her a lovely ride.
"She is off to visit Super Seth (Waikato Stud stallion) and we will then race her on and hope to pick-up another one (Group One won) if we can.
"I am absolutely thrilled she has a Group One now as she thoroughly deserves it."
Johnson was both delighted and a little relieved to secure the victory after being narrowly beaten on two occasions earlier in the day.
"It has been a long day and I'm very glad I held on to this one," she said.
"I kept her trotting and tried to keep her awake before the start, as she missed the kick the other day.
"I ended up getting on the back of Troy Harris (Prise De Fer), who I thought was the horse to beat and she has just been too good.
"He dragged me into the race and she is just so gutsy and really deserved the win today."
Bred and raced by Jim and Bill Gartshore, under their Gartshore Bloodstock banner, Savy Yong Blonk has now won eight of her 27 starts and over $486,000 in prizemoney.
She becomes the 24th individual Group One winner for Waikato Stud super stallion Savabeel, the winner of the Grosvenor Award (Champion NZ Sire) for six consecutive seasons.A sibling to Australian Group Two winner Adelaide Ace, Savy Yong Blonk is out of the Pins mare Ampin, and is also a three-quarter sister to Group One performer Strike The Stars.