Celtic must step it up in the cup - Leigh Griffiths

Leigh Griffiths has acknowledged that Celtic will be under pressure to win comfortably'' when they visit Stranraer in the William Hill Scottish Cup next Sunday.

The Hoops striker scored a last-gasp winner against Partick Thistle at Parkhead on Saturday after replacing struggling Nadir Ciftci at the start of the second half following an insipid display from the home side in the first 45 minutes.

Celtic midfielder Nir Bitton was sent off by referee Stephen Finnie in the 67th minute for picking up two yellow cards and while that seemed to spur on Ronny Deila's side, it looked like the Jags would take a point amid growing frustration within the home support.

However, Griffiths, back after a calf injury kept him out for four games, struck with a drive in the 89th minute - his 20th goal of the season - for Celtic's first home win since beating Aberdeen on Halloween, a victory that Deila probably needed'' according to the Scotland striker.

The win took the champions three points clear of the Dons at the top of the Premiership with a game in hand over the Pittodrie men, whose match at St Johnstone was cancelled due to a waterlogged pitch.

It was good to get back on,'' said Griffiths, who then turned his attention to the fourth-round cup tie against the League One side, where Celtic will look to keep their treble dreams alive.

There is going to be pressure on us to win the game, comfortably as well,'' said Griffiths.

But we will go down there, Stranraer will make it difficult for us.

We have to adapt to conditions and whatever team goes out we are confident of getting throughI think it will be the first time I will have been to Stair Park so hopefully it will be a good game, not too much trouble.

We look forward to it, the gaffer will look forward to it, he will have a game plan and will try to get into the next round.''

It was Thistle's first defeat in seven games but defender Dan Seaborne acknowledged they had been undone by a striker enjoying a great run of form.

He said: It was gutting to lose a goal so late in the game. Leigh is in great form so fair to play to him and the run he has been on, so it is one of those things you have to take.''