GLASGOW (AFP) - Celtic striker Jan Vennegoor of Hesselink admits the Parkhead side must get ugly if they want to hold onto their Scottish Premier League crown this season.

On Wednesday, their Glasgow rivals Rangers moved four points clear at the top of the table with a 2-1 win away to bottom of the table Gretna.

Although the Dutch international is still confident his side can secure their third title in a row, he warned the pressure is now on and silky soccer may have to be sacrificed to achieve their goal.

Speaking ahead of Celtic' s game at home to Kilmarnock on Saturday, the 29-year-old said: "At Celtic you need to win every game. We can't afford slip-ups and have to be focused.

"Sometimes we will be able to play nice football and at other times we might get the result by playing ugly football, but it's the points that count at this stage.

"Rangers are four points clear now and that means there is extra pressure on us as we can't afford to drop points.

"The priority is winning the game first and then playing good football as it's the wins which mean everything."

Saturday's game could be the perfect example of what Vennegoor of Hesselink is referring to.

The sides last met at Celtic Park on the opening day of the season and although the home side dominated they had to settle for a goalless draw.

However, Celtic have the added incentive this weekend of knowing victory would cut Rangers' lead to just a point, who have a tricky game on Sunday away to Inverness Caledonian Thistle.

Rangers were forced to work hard against Gretna at Fir Park to stretch their lead over Celtic and they will have to do so again when they face one of the current form sides.

Since Craig Brewster returned to the Highland side for his second spell as manager in late August they have shown a steady improvement.

In December they won five out of six games - including a 3-2 win at home to Celtic - and currently sit seventh in the table, only four points behind third placed Motherwell.

The pick of the other games this weekend is undoubtedly the Edinburgh derby where Hearts play host to Hibernian, who will have new manager Mixu Paatelainen in charge for his first league game.

Former Finnish international striker Paatelainen, who had two spells playing for the Easter Road club, was in charge for their 3-0 Scottish Cup victory at home to Inverness Caley.

While Hibs are seven points ahead of Hearts, neither will be happy with their league positions of eighth and 11th respectively.

The Tynecastle team will be desperate to start to pull away from second bottom, although they are still comfortably 11 points ahead of Gretna.

There could be another enthralling match at Tannadice when fifth placed Dundee United are at home to Aberdeen, who are one place and point better off than their hosts.

Third placed Motherwell are away to St Mirren in their first league game since the sudden death of captain Phil O'Donnell.

Fixtures (1500 GMT unless stated)

Saturday

Celtic v Kilmarnock, Dundee United v Aberdeen, Gretna v Falkirk, Hearts v Hibernian (1230 GMT), St Mirren v Motherwell.

Sunday

Inverness Caledonian Thistle v Rangers (1400 GMT).