The touring side were bowled out for 60 in the morning before England scored 274 for four to give themselves the perfect platform from which to secure the victory that would win back the Ashes.
"That was as tough a day as you can have as captain," Clarke told reporters.
"It was not a good toss to lose but Stuart Broad deserves a lot of credit for the way he bowled."
Broad completed figures of 8-15, scything through the Australian batting order with a superb display of fast bowling.
"There's no doubt we didn't bat well, but they were as tough a batting conditions as I have faced," said Clarke.
"You still have to have the skill to put the ball in the right areas and the England catching was exceptional."
Clarke was caught by Alastair Cook at first slip aiming an expansive drive at Broad.
"I tried to be as aggressive as possible," Clarke said. "I had watched team mates getting out trying to defend. You live by the sword and die by the sword."
Clarke, 34, refused to answer a question about whether he was embarrassed by his team's batting.
"I'll let you blokes write about that," he replied.
Clarke defended the decision to drop all-rounder Mitchell Marsh in favour of his brother Shaun, a specialist batsman.
"I think the selectors have been fantastic this series, they have been very open and honest with me," he said.
"As a captain you need to be as positive as you can be. It has been an extremely tough day but we have to turn up tomorrow and bowl England out.
"If we can then get a big score you never know what could happen."
