The Giants piled on the misery for their former coach as they scored seven tries to one in pulling off their first away win over St Helens since 1978.
"From one game to the next in the friendlies we showed some improvement and we trained to a standard where we were reasonably happy," he said."I thought we'd do a bit better than we did but we need to hold our nerve. It's a long year."
He went on: "But, at the end of the day, the physical part of the game is where it's won and lost and we got physically dominated.
"We knew Huddersfield had recruited really well and they will rattle up some scores.
"They did really well, hats off to them. Broughy got to play in a dinner suit tonight."
Under Brown, Huddersfield won at Wigan in the opening round last year only to fade in the second half and his successor Paul Anderson is determined to ensure his players do not get carried away with tonight's victory.
"It's fair to say we got the bounce of the ball but sometimes you make those things happen," Anderson said. "There was a good collective through the team but we can't lose sight of where we're at.
"My job is to keep people's feet on the ground. There were parts of the game where we were good and parts of the game where we weren't so good. There is still massive improvement to come.
"We will enjoy ourselves, understand where we're at and, when the time is right, put our focus into round two."