Pakistan is off to a very good start. They crawled along during the first session, but didn't lost a wicket against the fearsome pace triad of Mitchell Starc/Josh Hazlewood/Pat Cummins. The pitch at Brisbane offers equal amount of support for both the batsmen and the bowlers and I think that 300 plus would be a good first innings score that would give advantage to Pakistan. So far Shan Masood and Azhar Ali have done exceptionally well and if they could continue doing that during the post-lunch session then it will give Pakistan a real chance of upset.
BTW, a lot of the Pakistani fans may be excited about the test debut by pacer Naseem Shah. At 16 years and 279 days, he is one of the youngest ever players to make debut in international test matches (the record belongs to Hasan Raza, who made his debut aged 14 years and 227 days against Zimbabwe in 1996). Pakistan this time has completely changed their pace-attack and apart from Naseem, they have included young pace bowler Shaheen Shah Afridi, along with Imran Khan jr.