Glenn McGrath became only the eighth bowler to pass the 400-wicket mark in a Test match career as Pakistan fought to stave off an innings defeat.

Pakistan were forced to follow on after being dismissed for 221 and at the close were struggling on 176-8, still 47 runs adrift of Australia's first innings total.

McGrath joined the exclusive club when trapping Pakistani captain Waqar Younis lbw for six in the first session of the third day's play.

He is only the second Australian to achieve the feat. Shane Warne was the first.

Play began on Monday with Pakistan, who are seeking to avoid a 3-0 whitewash in the series, falling woefully short of Australia's 444.

Hasan Raza was the only player to show any resistance, top scoring with 54 not out in the first innings and 56 not out in the second.

McGrath has so far taken seven wickets in the match, with Warne one better on eight.

And a trim-looking Warne continued his purple patch with five wickets for 74 runs from 30 overs.

In their second innings Pakistan got off to a dreadful start when Taufeeq Umar was out for one run, when he edged a McGrath leg-cutter.

McGrath then claimed his 402nd Test victim when he trapped Younis Khan lbw for four shortly before tea and had the last wicket to fall in the day - Waqar Younis caught in the slips.

In the final session, Pakistan managed to get runs on the board, mainly due to the in-form Raza, but they were leaking wickets.

Rashid Latif, Saqlain Mushtaq and Misbah-ul-Haq were all victims of Warne's leg breaks as he helped himself to three more wickets for 56 runs.

However it was not all good news for Australia because opening batsman Justin Langer suffered concussion.

He was hit on the back of the nech while fielding at short-leg in the morning session as Raza pulled a short ball from Warne.

Langer missed the rest of the day, and suffered some concussion, but scans showed no serious injury.

Australia: Steve Waugh (capt), Matthew Hayden, Justin Langer, Ricky Ponting, Mark Waugh, Damien Martyn, Adam Gilchrist, Shane Warne, Brett Lee, Glenn McGrath, Andrew Bichel.

Pakistan: Waqar Younis (capt), Taufiq Umar, Imran Farhat, Younis Khan, Misbah-ul Haq, Hasan Raza, Faisal Iqbal, Rashid Latif, Saqlain Mushtaq, Danish Kaneria, Mohammad Sami. 12th man: Imran Nazir.

Umpires: Steve Bucknor (WIs), Srinivas Venkataraghvan (Ind)
Match referee: Clive Lloyd (WIs).