Pat Bonner
Former Celtic goalkeeper on BBC Sportsound

How did that stay out?

It's AZ who look to be finishing the stronger, but Celtic burst to life again and are only denied by two tremendous stops from the AZ goalkeeper and a goalline clearance.

Tony Ralston bursts to the byline and Odsonne Edouard's shot is blocked by Hobie Verhulst, the striker's header is then scooped off the line then Adam Montgomery's header is cleared by the forehead of Bruno Martins Indi.

Incredible...

James McFadden
Former Scotland forward on BBC Sportsound

Substitute James McCarthy is booked for a foul that results in a free-kick launched into the Celtic penalty box, but the home side survive the pressure.

Yet another change and it's a big moment for 17-year-old striker Ernest Poku, who made his AZ debut at the weekend.

The academy graduate replaces new signing Vangelis Pavlidis, who has had a quiet game after a lively early spell in his first start.

Celtic boss Ange Postecoglou responds with two changes of his own.

Tom Rogic and Kyogo Furuhashi, goal creator and goal scorer, leave the field, with James McCarthy and Adam Montgomery come into the home midfield.

A double change from the visitors as they try to reverse the tide.

Netherlands' Jordy Clasie and Norwegian 21-year-old Hakon Evjen come into midfield in place of striker Ilbert Gudmundsson and Fredrik Midtsjo.

James McFadden
Former Scotland forward on BBC Sportsound

Image source, SNS

Talking of Celtic defenders, one former Hibs man isn't so impressed with Carl Starfelt, their summer signing from Rubin Kazan...

What a clearance from Tony Raltson.

The often maligned right-back slides in to intercept a dangerous cross low into the Celtic penalty box. His recent performances have certainly answered his critics and he might have a long-term career with the Glasgow club yet.

James McFadden
Former Scotland forward on BBC Sportsound

Just when Celtic's intensity appeared to be dropping, they burst into life again to double their lead.

Kyogo Furuhashi turns provider this time, finding James Forrest with his back to goal about eight yards out and, when the winger shoots on the turn, it deflects wickedly off defender Timo Letschert and spins wide of goalkeeper Hobie Verhulst.

Image source, BBC Sport

Pat Bonner
Former Celtic goalkeeper on BBC Sportsound

Liel Abada's return from injury led to Odsonne Edouard dropping to the bench.

But the Israeli winger has run out of gas and on comes the French striker, which means a bit of tinkering with the Celtic formation.

Zakaria Aboukhlal is at the centre of everything good for AZ and this time the Morocco forward's shot takes a deflection, leaves goalkeeper Joe Hart flat-footed but finds the side netting.

AZ should be level as Zakaria Aboukhlal bursts deep into the Celtic penalty box and cuts it back neatly into the path of Thijs Oosting.

However, the left-back fires wildly over the crossbar from 10 yards.

AZ's Dani de Wit is the first to go into the referee's book with a wee elbow into the face of opposition midfielder Tom Rogic.

Celtic get the second half under way.

Can they build on that lead, or will AZ hit back ahead of next week's second leg?

No changes by either side at the break.