* Smith, Khawaja score half-centuries
* Smith declines to make Pakistan follow on (Updates at dinner)
Dec 17 (Reuters) - Captain Steve Smith and Usman Khawaja scored half-centuries to drive Australia to a mammoth lead of 489 with five wickets in hand at dinner on day three of the first day-night test against Pakistan in Brisbane on Saturday.
Usman Khawaja scored 74 and captain Steve Smith smashed 63 off 70 balls as the home side sought to bat Pakistan out of the game after declining to enforce the follow-on on a steamy day at the Gabba.
Australia were 202 for five in their second innings, with Peter Handscomb unbeaten on 35 and wicketkeeper Matthew Wade on one.
Smith declined to declare the innings closed before the break but is likely to put Pakistan in to bat quickly in the evening session with the pink ball at its most devilish.
Pakistan were bowled out for 142 before tea, 287 runs short of Australia's first innings 429 and 88 shy of making their opponents bat again.
The tourists were buoyed by two early wickets late in the second session but Smith and Khawaja wrested back the momentum on a sun-baked pitch that offered little succour for the bowlers.
Smith, who top-scored with 130 in the first innings, was eventually dismissed by leg-spinner Yasir Shah after slogging to Rahat Ali at long-on.
Khawaja was out for 74 with Pakistan captain Misbah-ul-Haq taking a fine catch off the bowling of Rahat.
Opener David Warner was earlier out for a free-swinging 12, skying a pull shot off Mohammad Amir for an easy catch at mid-on for Wahab Riaz.
Rahat grabbed his first wicket of the match when he had opener Matt Renshaw edge to Younus Khan for six in the slips.
Routed by Australia's seamers late on day two, Pakistan resumed in the afternoon on 97-8, and wicketkeeper Sarfraz Ahmed and Mohammad Amir built a plucky 54-run partnership before paceman Jackson Bird struck to remove Amir for 21.
Rahat was run out for four with a piece of typical fielding brilliance from Warner to wrap up the innings, leaving Sarfraz stranded on 59. (Reporting by Ian Ransom in Melbourne; Editing by Sudipto Ganguly)