Gary Mackay-Steven took less than 40 seconds to mark his Celtic debut with a goal as they take a 2-0 lead in at half time away to Partick Thistle.

Stuart Armstrong, who was also making his Bhoys debut, netted on the half-hour mark as the visitors took in a commanding lead at the break.

Mackay-Steven gave the visitors the lead after 38 seconds when he steered a shot underneath Partick goalkeeper Scott Fox.

The home side almost responded instantly in what was a frantic opening few minutes, but Virgil van Dijk was on hand to head clear.

Nir Bitton was next to try his luck for Celtic, but the midfielder dragged his effort wide after a good move to work the space for the shot on 18 minutes.

However, Armstrong was not to be outdone by his fellow debutant, and he extended the lead on the half-hour mark on his own maiden start for the club.