Hearts booked a Scottish Gas Scottish Cup quarter-final clash with Morton after a first-half blitz powered them to a 4-1 victory at Airdrie.

Lawrence Shankland was yet again the key man for Steven Naismith’s side, with the captain bagging a brace to take his tally for the season to 24.

Shankland fired the Jambos in front and despite a positive response from the home side, the game was soon almost out of reach.

Kenneth Vargas and Calem Nieuwenhof both found the net to have the visitors on easy street with just 21 minutes on the clock.

There was a glimmer of hope for the Diamonds following Adam Frizzell’s glancing header after 34 minutes, but Shankland would add a decisive fourth with 17 minutes remaining to cap off an emphatic victory.

Craig Gordon returned between the sticks for the visitors, with Naismith making three changes from the side that defeated St Johnstone in midweek.

Jorge Grant and Craig Halkett were also handed starting roles, replacing Frankie Kent and Scott Fraser.

Arron Lyall made his first start for Airdrie since joining the club on loan from Rangers, the 20-year-old coming in for Liam McStravick.

The game began at a frantic pace and the home side forced three corners in the opening 10 minutes.

Hearts struck first in the 11th minute following a sweeping passing move that ended with Shankland powering home Alex Cochrane’s cutback.

Despite suffering an early setback, Airdrie responded well and looked to take the game to their cinch Premiership opponents.

Lyall’s cross almost caught out Gordon, but drifted just wide of the target, before Nikolay Todorov forced a wonderful close-range stop from the Hearts goalkeeper.

The Jambos survived a huge scare when Mason Hancock’s header from Charlie Telfer’s corner cannoned back off the crossbar.

Airdrie would be punished for not taking the chances that came their way when Kenneth Vargas doubled the visitors’ lead. The Costa Rican striker raced on to Halkett’s perfect through pass before prodding the ball past Josh Rae.

Suddenly, the Diamonds were facing a rout and they would concede again three minutes later after Nieuwenhof angled a low drive into the bottom corner.

Hearts were now cruising, though they would be dealt a blow when Halkett limped off to be replaced by Kye Rowles.

Alan Forrest worked Rae with a fizzing volley before the hosts gave themselves a glimmer of hope by reducing the deficit.

Hancock picked out Frizzell with a pin-point cross and the Airdrie skipper glanced beyond Gordon.

Rae denied Forrest and Dexter Lembikisa’s long-range strike either side of half-time as Hearts looked to put the game beyond doubt, but the hosts continued to demonstrate a threat of their own.

Lewis McGregor’s cross almost dropped under the crossbar with Gordon scrambling, and the introduction of Calum Gallagher for the final 23 minutes added an extra dimension to the Airdrie attack.

Any hopes of a shock comeback were extinguished after 73 minutes when Shankland was released by Fraser and the striker produced a typically composed finish to dink over the keeper.