Given time to reflect, Rich Hill Stud boss John Thompson is getting immense satisfaction from Saturday's red-letter day for the Matamata farm.

Rich Hill Stud stallions sired the winners of both Group One races run in Australasia on Saturday: Shocking's son I'm Thunderstruck producing a dazzling finish to secure a narrow win in the Gr.1 Makybe Diva Stakes (1600m) at Flemington, while closer to home Proisir four-year-old Dark Destroyer won the Gr.1 Tarzino Trophy (1400m) at Hastings.

"People who don't stand stallions probably don't understand the resources you have to put into them and what goes on to try and make them a success and that's why it's such a great feeling when you have a day like we did on Saturday," Thompson said.

"It was really satisfying but it's such a busy time of year at the moment. You enjoy the moment but you're always thinking about what you've got to do the next day too."

Group One success will only increase the popularity of both stallions with breeders again this season but Thompson said while he welcomed the increased workload, he wanted to savour the moment.

"Often you have these horses in these races and you think beforehand, it would be great if they could all win but more often than not you go home disappointed," Thompson said.

"But it all came together on Saturday and was a great result, an exciting weekend for everyone involved.

"Shocking had such a great season last year and this is just a continuation from that. And we all know Priosir is a horse on the up. He started off at a $7000 service fee and he's just done such a good job.

"The market overlooked Dark Destroyer a bit but he was favourite for a Group One in Australia when he ran fourth in the Queensland Derby (Gr.1, 2400m) so we knew he was a Group One animal. Andrew (Scott) and Lance (O'Sullivan) had him ready on the day and (owner) David Archer's luck continued.

"It will be interesting to see how the horse goes now because we know that he stays. He might be a chance to win the triple crown at Hastings."

It was the third time a Rich Hill stallion had provided owners David Archer and Diane Wright with a Group One winner after Pentire's 10-time Group One winner Mufhasa and Jimmy Choux's three-time Group One winner Bostonian.

"You've got to hand it to David. That horse was passed in at the sales but David went back and looked at him again and bought him. He's certainly got an eye for a good horse," Thompson said.

Proisir's service fee stands at $17,500 + GST and Thompson said he continued to find favour with breeders.

"The last few years his books have been bigger and quality is the key thing now. He's proven he can upgrade mares," said Thompson, who expected Dark Destroyer's win would see breeders fill his remaining service slots.

"All these horses were conceived off a $7000 service fee and he's hardly had a yearling in Book 1 at the sales. But that's all going to change. This is his best crop of yearlings this year and he's got another lovely book of mares to serve.

"He's always sold well but his better quality mares are coming through now and this will just add to his profile. It's already pretty high. Everyone knows what he's achieved off the lesser quality mares so when the progeny of the really good mares start hitting the sales ring, that will be the key."

Dark Destroyer became Proisir's second individual Group One winner after Levante, who secured the Telegraph (1200m)-BCD Group Sprint (1400m) double last season.

I'm Thunderstruck added to his previous Group One win in the Toorak Handicap (1600m) and to Shocking's previous Group One winner Fanatic, in the 2016 New Zealand Oaks (2400m) at Trentham.

"Halfway down the straight Alligator Blood had skipped clear and he wasn't stopping and you thought he'd run a rather unlucky second because he was held up but the last 50m he just showed how much he wanted to win," Thompson said.

"People might overlook the fact that Shocking won that race himself. I know the Melbourne Cup is his big profile race but he did win the Makybe Diva Stakes too. 

"He had another really nice winner at Ruakaka too in Vegas Strip. He seems to get winners every week, Shocking. All distances and both sexes. He was second-leading stallion in Australasia last season for stakes winners to runners which is a pretty fair feat."

It was the second time Rich Hill stallions had produced two Group Ones on a day after Pentire gelding Pantani won the Gr.1 Adelaide Cup (3200m) and Bahhare filly Dowry won the Gr.1 South Australian Oaks (2500m), both at Morphettville on May 17, 2004.

"Group Ones are Group Ones for a reason. There's only so many of them and they're bloody hard to win," Thompson said.

"When you get the opportunity to stand these horses, you do it because you think they have the right credentials to be successful, good racehorses with good pedigrees and lovely looking horses but that doesn't guarantee success. So it's pretty satisfying how it's all come together and how well the last 12 months have gone."

In Shocking, Proisir, Vadamos, Satono Aladdin and Ace High, Rich Hill Stud boasts a remarkably strong roster at present.

"Pentire set the benchmark. He sired 16 Group One winners and you could reel off some greats of the turf with horses he sired," Thompson said.

"But this would have to be the strongest roster we've had across the board at any one time at the moment. There's a tremendous amount of talk about Satono Aladdin's progeny and we've Ace High coming through now too. You could breed to any one of them with confidence and that's a pretty big statement.

"It's great for New Zealand too. Our breeding industry, stallion-wise is in great shape at the moment. We just need that investment in broodmares at the moment but our horses just keep performing in Australia and it just shows we've got the stallions to be doing that."