For the second time in just over 40 minutes at Rosehill on Saturday, Clark defied the chasers as In The Congo's Group 1 $1m XXXX Golden Rose (1400m) win followed stablemate Vangelic's barrier to box performance in the Group 2 $400,000 Golden Pendant.
Clark, who also won the Colin Stephen on Entente for Tulloch Lodge, said he was always going to lead on In The Congo but any thoughts of taking it easy midrace were scuppered quickly by Waterhouse.
"I had a conversation with Gai on the way here and I said to her I'll roll to the first turn and might just try and get a breather,'' he said.
"She said 'don't you dare'. She said you keep him running and use his speed because it can win you the race. So I did that and we pulled it off."
It was Clark's 18th career Group 1 and, amazingly, the first Golden Rose both for Gai Waterhouse and her partnership with Adrian Bott.
After establishing the lead Clark kept them running as he promised Waterhouse and after shaking off a brief challenge from Remarque he dashed away and held off the $1.90 favourite Anamoe to win by a long head with Coastwatch 1-1/2 lengths away in third.
Clark said In The Congo has been a quiet achiever who has continued to improve with racing and was rapt to turn the tables on Anamoe from their Run To The Rose clash two weeks earlier.
"He has probably looked as good today as he has looked all prep. He is obviously thriving and all the team who look after him at Tulloch Lodge have done a wonderful job,'' he said.
"They've presented all their horses well today. It's a big thrill. We've always thought he had that sort of ability. He probably didn't execute early on in his career.
"He had that little short let up and he's come back and got it right every time although he hasn't won every time. I thought he went even better again."
Co-trainer Adrian Bott said he wasn't concerned about going to the 1400m for the first time, particularly with how results through the afternoon panned out and leaders were getting their chance.
He said with that in mind it was important that Clark made the Golden Rose a test to put a horse like Anamoe out of play as much as possible.
"He has the ability to sustain that (run) and that was what we wanted to do today, take away some of their brilliance and bring in his assets like his high cruising speed and that toughness that he's got,'' he said.
"He wears his heart on his sleeve every time he steps out. He was deserving a tough victory like this."
It's been quite a rise for In The Congo who made his debut with a win in a midweek race on the Kensington track in May and contested all three major lead up races to the Golden Rose.
They resulted in a second in the Rosebud, win in the San Domenico and that narrow defeat in the Run To Rose so he's certainly been a busy boy.
"Every start he has stepped out he has surprised me and continued to impress me and improve,'' Bott said.
"We have kept raising the bar from when he stepped out in the off season in the Winter and through the early stages of the Spring. We set him goals and he kept delivering. He's still been putting it all together but he has put it all together in a big way now."
As for the future, Bott said consideration would be given to the Coolmore Stud Stakes in November.