The Ashes: Haddin drop costs Australia 134 runs

Brad Haddin watches on as Joe Root celebrates his century. Photo / AP

Brad Haddin has dropped easier catches, but few would sting as much as the reprieve offered to Joe Root on day one of the Ashes opener.

England would have crashed to 4-43 in Cardiff if Haddin held the one-handed attempt, when Root had yet to score.

By stumps they were 7-343, Root having scored a sparkling 134 on a pulsating day.

Haddin moved late to the right, the ball smacking into his extended glove then popping out.

"They're always tough those really full ones and Hadds usually takes more than he drops," Josh Hazlewood said of Haddin, who snaffled a sharp catch to dismiss Alastair Cook.

"We built pressure and then just leaked the runs and the pressure went away."

Root steadied in style, reaching three figures in 118 balls to make it the fastest first-innings ton in Ashes history.

The vice-captain was eventually out edging to Mitchell Starc in the 73rd over, having rebuilt England's innings with the help of Gary Ballance and Ben Stokes.

Root suggested he was fortunate to cash in - on the error and Michael Clarke's aggression.

"When you lose three wickets quickly you are going to get opportunities to score because they're going to have aggressive fields," Root said, revealing he would have reviewed the catch thinking it was a bump ball.

"It could have gone completely the other way.

"If I got out second ball, you look a bit silly.

"Thankfully he didn't manage to cling on to it."

Ballance contributed 43 runs in a 147-run partnership with Root, who then put on a 84-run stand with Stokes before attempting one cover drive too many.

Hazlewood felt it wasn't so much the dropped catch, but the way his side bowled afterwards that helped England fight back.

"I don't think we are used to dropping catches at the moment," he said.

"Hopefully we don't, but in that situation I think we have got to deal with it better and keep bowling balls in the right area."

Hazlewood did plenty of that in his first Ashes Test.

The right-armer maintained a full length for 22 overs, dismissing Ballance, Adam Lyth and Jos Buttler to be the pick of the bowlers.

Starc trapped Ian Bell lbw and created the only two chances of Root's four-hour knock, while he rattled Stokes' stumps after a quick-fire 52.

However, the left-armer struggled for control and consistency for much of the day and went off late with a sore ankle.

Australia grabbed four wickets in the final session, but until Moeen Ali is back in the sheds Hazlewood won't feel too comfortable.

"He's quite a clean hitter of the ball," he said of Ali, who will resume on 26 alongside Stuart Broad.

"We can attack the other three guys and knock them over as quickly as we can and get batting."

- AAP