Australia end the day 300 ahead with Nathan Lyon stuck on 499 Test wickets

Offspinner Nathan Lyon remained tantalisingly on 499 Test wickets before Steven Smith and Usman Khawaja survived hostile bowling from Pakistan's improved attack late on day three as Australia built a big lead in the first Test at the Optus Stadium.

After expectedly not enforcing the follow-on having spent 101.5 overs in the field, Australia slumped to 5 for 2 in their second innings after the wickets of David Warner and Marnus Labuschagne. But Smith and Khawaja steadied them with an unbroken 79-run partnership as Australia reached stumps with a lead of 300 runs.

The pitch started to show more bite as the day wore on, with Smith having to endure a short-pitched assault from spearhead Shaheen Shah Afridi. Smith needed medical attention just before stumps after an Afridi delivery whacked into his forearm. Nevertheless, Pakistan face a daunting task to avoid a 15th straight Test defeat in Australia.

Trailing by 216 on first innings, Pakistan's slim hopes were briefly raised after inspired new-ball bowling in contrast to an underwhelming effort in Australia's first innings. Afridi shrugged off an erratic display earlier in the match as he settled into a consistent line and length, although his speeds only nudged the mid-130kph mark.

But it was debutant quick Khurram Shahzad who summoned extra spice from the surface with the wickets of Warner and Labuschagne from short-pitched deliveries in the opening eight overs. Having made an emphatic century on day one, Warner fell for a duck when he miscued a pull to midwicket.

Shahzad continued his impressive debut with a rearing delivery jumping at a length to slam the finger of Labuschagne, who sought medical attention immediately. Labuschagne appeared rattled after that, and it may have contributed to his ungainly dismissal when he fell to backward square. Australia scored only seven runs in the first ten overs in a major contrast to scoring over four runs an over during their first innings, but Khawaja and Smith settled to thwart Pakistan's long haul back into the series opener.

Earlier in the day, Pakistan's batters succumbed to Australia's formidable attack, and they scored at just 2.66 runs an over. It was a major contrast to the proactive brand of batting promised ahead of the match by new captain Shan Masood. But Pakistan's struggle was also testament to the quality of Australia's bowling during batting-friendly conditions early on day three.

Showing no signs of fatigue after a taxing year - and less than a month since Australia's World Cup triumph - quicks Pat Cummins, Josh Hazlewood and Mitchell Starc claimed five wickets between them. Cummins and Hazlewood, particularly, were tireless but also luckless as wickets were distributed among all the six bowlers used. Starc was erratic at times, but clean bowled wicketkeeper Sarfaraz Ahmed, who was retained in the team over Mohammad Rizwan, with an astounding swinging delivery that knocked over off stump.

Before that, the first hour of play was dominated by a riveting battle between Cummins and talisman Babar Azam in a pivotal phase of the match. Babar was pinned down by typically accurate bowling from Cummins, and the former did not get off the mark until his 13th delivery when he blasted a full delivery through the covers for a boundary.

But he had to endure several nervous moments when an inside edge narrowly missed the stumps, leading to a frustrated Cummins resorting to a bouncer that flew over wicketkeeper Alex Carey, and to the boundary. Babar survived Cummins' onslaught, and built a blossoming partnership with opener Imam-ul-Haq, who notched a gritty half-century to help banish the ghosts of a double failure in Adelaide four years ago in his only previous Test in Australia.

But Babar on 21 fell to a superb delivery from allrounder Mitchell Marsh, who continued his stellar performance on his home ground after making 90 in Australia's first innings. Babar's dismissal rattled Pakistan, with Imam's 199-ball defiance ending in ugly fashion when he charged down the pitch to Lyon on 62, but failed to make contact and was stumped.

Having taken three wickets in the innings, the tension was palpable as Lyon tried to claim his 500th Test wicket late in the second session, and wrap Pakistan's first innings up. But he was thwarted by Salman Ali Agha and Afridi, who ultimately holed out to part-time spinner Travis Head as the fans in the terraces groaned.

Lyon, who made his return from a calf injury that had cut his Ashes campaign short earlier this year, will have to wait just a little bit longer to become the eighth bowler to reach the landmark, and join Glenn McGrath and Shane Warne as the only Australians to do so. His impending milestone adds some intrigue to a match that appears headed for an inevitable Australia victory.