Celtic began their Scottish Premiership title defence with a narrow home victory as Benjamin Nygren's header downed Dundee.

After a drab first half, Sweden midfielder Nygren met a magnificent cross from Kieran Tierney on 52 minutes for the game's only goal.

Tierney was one of Celtic's key performers last term as they chased down Hearts in a thrilling finale, and he stood up with a moment of quality once more to start the new campaign.

The margin of victory could have been more comfortable for Martin O'Neill's side had Arne Engels and club-record signing Kasper Hogh not spurned gilt-edged chances in the first half.

There was more wasteful finishing after the break, with Hogh poking wide and substitute Sebastian Tounekti firing well over the top after some neat footwork created the opening.

Callum McGregor appeared to have added a deserved second when he curled a right-footed shot towards the top corner, but it bounced to safety off the post.

Dundee had their moments - Charlie Reilly rippled the side netting after a neat lay-off from Simon Murray in the first half and Ashley Hay's header forced a fine save from Celtic goalkeeper Viljami Sinisalo late on.

However, Celtic saw the game out without alarm to take all three points.

As is so often the case in the off season, the focus at Celtic has been on the transfer market and whether their squad is equipped to compete both domestically and in Europe.

Hogh and Camilo Duran are the only summer arrivals so far at Parkhead and both were handed debuts from the start.

Duran was shifted out wide to accommodate Hogh playing through the middle and the game largely passed the Colombian by, with a neat second-half turn his sole highlight.

Hogh was more involved and probably should have got his first Celtic goal, but failed to hit the target with any of his four shots inside the Dundee box.

Instead, it was three established stars who delivered amid a slightly rusty display.

Tierney's cross was typical of a player who creates plenty of goals from full-back, Nygren opened his account for the season with a straightforward header after scoring 21 times last season, and McGregor drove standards from midfield as he so often does.

There will almost certainly be further incomings and outgoings at Celtic in the coming weeks, but those core players are who O'Neill will rely on to lead the way.

From a Dundee perspective, Pressley spoke of how proud he was of his team post-match and you can understand why.

The visitors put in a huge effort defensively and had their moments at the other end.

Centre-back duo Ryan Astley and Owen Bevan were outstanding, making nine interceptions and 15 clearances between them.

On paper, this is their toughest league game and they return to Dens Park having limited the damage.

Celtic manager Martin O'Neill: "The most important thing is to win the game.

"We created a number of chances, but I didn't think we played particularly well. We could have played with more intensity - it was a typical opening game of the season.

"[Kieran Tierney and Callum McGregor] are the football club. They are the backbone of Celtic and it's great to see them playing together again."

Dundee manager Steven Pressley: "I'm exceptionally proud of the group. We're in a real transitional moment.

"We were incredibly brave with the ball and without the ball. Also, I couldn't be prouder of how hard they worked tonight.

"It was an exceptional performance and one we can certainly build on. I was really pleased. I was truly proud of the players' performance.

"Our two centre-backs were outstanding tonight, but we do need depth in that area."

Celtic are away to Kilmarnock on Sunday (13:30 BST), while Dundee host Aberdeen on Saturday (15:00).