Usman Khawaja leads Australia's strong reply in opening Ashes Test

Opening batsman Usman Khawaja scored his first century in England to help Australia fight their way back in the opening Ashes Test at Edgbaston on Saturday.

Khawaja remained unbeaten on 126 as the visitors reached 311-5 at close of play on day two, trailing by 82 in the first innings.

Earlier, Stuart Broad's two wickets in two balls, which removed David Warner for the 15th time and handed a first-ever golden duck in international cricket to Marnus Labuschagne, gave England a perfect start on Saturday.

The Test champions were struggling on 78-3 at lunch after Ben Stokes took the key wicket of Steve Smith. But a counter-attacking innings from Travis Head and sensible batting by Khawaja led the recovery.

Khawaja's hundred was completed with a late-cut four off Stokes.

The left-handed batsmen's stay appeared to be over when Broad bowled him for 112 in the first over with the new ball. But replays showed the seamer had overstepped.

Broad had earlier reduced Australia to 29-2 as he again got the better of Warner, whom he dismissed seven times during the drawn 2019 Ashes in England.

The left-hander had reached nine on an overcast morning favouring England's quicks when he chased a wide ball from Broad and inside edged into his stumps.

"LOL"#EnglandCricket | #Ashes pic.twitter.com/hNHY3Owd0s

And the roars of the crowd became deafening next ball when Labuschagne, the world's top-ranked Test batsman, fell for a duck after edging a Broad outswinger that was brilliantly caught by diving wicketkeeper Jonny Bairstow.

Smith survived the hat-trick delivery but did not look comfortable. His innings was cut short when Stokes rapped Smith on the back foot with a ball that cut back in.

As the ball got older and conditions for batting eased,