Australia skipper Tim Paine won the toss Friday and elected to bat in gloomy conditions and with rain in the forecast.
The Australian openers shared a 222-run opening stand in first test last week, setting the hosts on course for a 580 total and an innings victory at the Gabba. But Joe Burns (4) only lasted 3.3 overs at the Adelaide Oval before he was caught behind off Shaheen Afridi to make the total 8-1.
Warner, who scored 154 last week in a return to form following a forgettable Ashes series, stroked a cover drive to the boundary off recalled Mohammad Abbas to get within a shot of half century.
He shared a 62-run second-wicket stand with Marnus Labuschagne, who was unbeaten on 18 at the interval. Labuschagne, who narrowly avoided a first-ball duck against Shaheen, scored a career-high 185 last week and is growing in confidence as Australia's No. 3.
The Australians stuck with the same XI that won the series opener last weekend by an innings and five runs.
Pakistan made three changes, including a recall for Abbas and a test debut for 19-year-old Muhammad Musa at the expense of Imran Khan and Naseem Shah.
Shaheen had the only breakthrough of the first session, returning 1-10 from seven overs. Abbas had figures of 0-29 from 10 overs and Musa had a costly opening five overs that went for 31.