A moment of brotherly love on the fourth afternoon at Sydney very nearly went awry for Mitchell and Shaun Marsh, when the pair were forced to scramble back to their creases to avoid a run-out after prematurely celebrating Mitchell's century.

The incident took place towards the end of their 169-run stand for the fifth wicket, when Mitchell Marsh, 0n 99, punched Tom Curran through the covers, and set off in jubilation for the decisive run.

However, the ball had not gone for four, and so was still in play when the pair turned to embrace in mid-pitch, leading to "a quick split-second of panic", a feeling that was shared by Australia's captain, Steve Smith, who was shown on TV gesticulating wildly from the dressing-room balcony before swearing under his breath as the crisis was averted.

"He had a bit of a laugh when we got in the change rooms but it was one of those things that worked out pretty well in the end," Shaun Marsh said. "It was pretty funny.

"That was my fault. Emotions got the better of me and I just wanted to give him a hug. I lost all concept of where the ball was ... he pushed me off and said: 'You better get to the other end.' Thankfully it all worked out well. I was very happy for him."

"I pretty much went for the high five and Shaun went for the hug and we parked in the middle and had a quick split second of panic and then hugged again after that," Mitchell Marsh said.

The embarrassment at being run out while celebrating a century would have been acute for the younger Marsh. However, it's possible that he still wasn't fully composed by the time he faced his very next delivery from Curran, which bowled him off an under-edge.

Nevertheless, in making their second centuries of a fine Ashes campaign, the Marshes became the first Australian brothers to score hundreds in the same innings since Steve and Mark Waugh managed it at The Oval, also in a fifth Test against England, in 2001.

"We both had a pretty rough night's sleep," said Mitchell Marsh. "Just to be out there to watch Shaun hit that cover drive and embrace him in the middle when he got his hundred and for him to be out there for mine and help me when I was in the 90s and nervous ... we'll look back on it in a few years and cherish it."