GLASGOW (Reuters) - Scott McDonald grabbed two goals as holders Celtic coasted to a 5-1 Scottish FA Cup fifth round win at Kilmarnock on Saturday.

Zander Diamond score the only goal in Aberdeen's 1-0 win over second division Hamilton Academicals, while St Mirren and Dundee United slugged out a goalless draw.

McDonald blasted the opener for Celtic in the 22nd minute from a couple of metres as he ran in to meet a low cross from Paul Caddis on the right.

Celtic eased into a 2-0 lead in the second half when Gary Caldwell headed home in the 52nd minute after Italian Massimo Donati flicked on a corner by Japanese midfielder Shunsuke Nakamura.

Jan Vennegoor of Hesselink scored the third after Kilmarnock lost possession in midfield and Aiden McGeady burst clear to feed him on the left. The Dutch striker then rifled a rising shot into the top left from 20 metres.

Kilmarnock's Jamie Hamill guided a downward header into the net from five metres following Australian forward Danny Invincibile's cross in the 66th minute. A minute later McDonald rammed in Celtic's fourth before being replaced by Georgios Samaras.

The Greek forward ended a fine diagonal run by sweeping a low shot around Alan Combe into the far corner to complete the rout.

In other matches featuring second division teams, Livingston drew 0-0 with Partick Thistle, while Morton slumped to a 2-0 home defeat by Queen of the South with a header from Sean O'Connor in the 46th minute and a late strike from substitute John Stewart.

Hibernian face Rangers on Sunday, while two ties were postponed; Motherwell v Dundee and third division Ross County v St Johnstone will be played later this month.

(Editing by John Mehaffey and Pritha Sarkar)