Scott Sinclair scored a hat-trick as holders Celtic thrashed St Johnstone 5-0 at Parkhead to seal their place in the William Hill Scottish Cup quarter-finals.

The Hoops forward squeezed in the opener after three minutes before skipper Scott Brown thundered in a 30-yard drive six minutes later.

Returning winger James Forrest added a third in the 52nd minute, with Sinclair scoring twice more to seal victory in a one-sided affair.

Joining Celtic – looking to win the competition for the third successive season – in Monday night's draw for the last eight are Scottish Premiership rivals Aberdeen and Hearts, who both recorded similarly convincing wins on Sunday.

All five goals at Pittodrie came in the second half as the Dons overcame Ladbrokes Championship outfit Queen of the South 4-1.

Half-time substitute Niall McGinn was the star of the show for the hosts, including netting a 47th-minute opener before the prolific Stephen Dobbie quickly levelled for Queens with a stunning strike.

Winger McGinn then turned provider for Andrew Considine and Sam Cosgrove to fire Aberdeen into a 3-1 lead by the 67th minute.

Cosgrove would add a fourth from the penalty spot for Derek McInnes' 2017 runners-up, who are looking to win the Scottish Cup for the first time since 1990.

Hearts, meanwhile, were 4-0 winners over Junior minnows Auchinleck Talbot at Tynecastle.

First-half goals from Christophe Berra, Demetri Mitchell and Steven MacLean ensured Auchinleck would not cause another upset, having dumped out high-flying Ladbrokes Championship side Ayr in the fourth round.

Substitute Aidan Keena then added a late fourth for the home side – the 19-year-old's first senior goal for the club.