Match ends, Dundee 0, Celtic 2.
Leigh Griffiths and Stefan Johansen were on target as Celtic cruised into the quarter-finals of the Scottish Cup.
Griffiths glanced home an early header and the visitors had several chances to add to their lead before the interval.
They took their first of the second half though, when Johansen netted from close range after Griffiths' header had been saved by keeper Scott Bain.
Dundee offered little in attack but Bain produced some excellent saves to keep the score down.
The hosts sealed their spot in the fifth round thanks to a 2-1 home win over Aberdeen and went into Saturday's match on a six-game unbeaten run.
Celtic hammered 4-0 at Tynecastle to set up their trip to Dens Park, and went into the game having won their last five.
With Luka Tankulic, Craig Wighton and Greg Stewart in the Dee starting line-up, manager Paul Hartley stuck to his pre-match vow to attack the Scottish Champions.
It was the visitors who looked the more threatening though and they hit the front through former Dundee man Griffiths.
Right-back Mikael Lustig provided the perfect cross from the right and Griffiths nipped in between centre-backs James McPake and Kostadin Gadzhalov to nod past Bain into the corner.
McPake made a superb challenge to stop Johansen before Scott Brown and James Forrest had sights of goal, but neither found the target.
Johansen then played in Forrest but the winger's effort was well saved by Bain and McPake knocked the ball to safety with two Celtic players waiting to pounce.
Dundee, who saw top scorer Greg Stewart go off injured, had their first shot on goal through defender Gadzhalov, but his well-taken volley drifted wide.
After excellent link-up play from Lustig and Commons on the right, Griffiths produced a glorious first touch to dink the ball over a defender's leg and create a chance, only to see his volley blocked by Bain.
Celtic had chances to add to their lead through Johansen and Griffiths but Bain beat away the former's effort and the latter could not keep his volley down, while visiting keeper Craig Gordon made a stop to keep out Paul McGowan's deflected effort.
The second goal arrived straight after the break. Lustig again found Griffiths in the area and after his header was parried by Bain, Johansen was there to knock the ball into the net.
Commons had gone off at the break with a hamstring problem and he was joined in the dressing room by Lustig after he picked up a knock.
As the hosts struggled to contain Ronny Deila's side, keeper Bain touched a Johansen cross on to his own post.
Dee did come into the game more as an attacking force but could not create clear-cut chances and the visitors always looked the more likely, with Griffiths a constant threat.
Celtic's display merited more goals but they had to settle for two, while Hartley will know his side failed to play to their potential.
- 3DyerBooked at 57mins
- 15StewartSubstituted forMcGinnat 36'minutes
- 21TankulicSubstituted forBlackat 90'minutes
- 33WightonSubstituted forClarksonat 58'minutes
- 23LustigSubstituted forMatthewsat 55'minutes
- 5van Dijk
- 49ForrestSubstituted forGuidettiat 74'minutes
- 15CommonsSubstituted forStokesat 45'minutesBooked at 56mins
- John Beaton
- Shots on Target
Second Half ends, Dundee 0, Celtic 2.
Substitution, Dundee. Andrew Black replaces Luka Tankulic because of an injury.
James McPake (Dundee) wins a free kick in the attacking half.
Foul by John Guidetti (Celtic).
Foul by Luka Tankulic (Dundee).
Scott Brown (Celtic) wins a free kick in the attacking half.
Luka Tankulic (Dundee) wins a free kick on the left wing.
Foul by Scott Brown (Celtic).
Kostadin Gadzhalov (Dundee) wins a free kick on the right wing.
Foul by John Guidetti (Celtic).
Foul by David Clarkson (Dundee).
Anthony Stokes (Celtic) wins a free kick in the attacking half.
Paul McGowan (Dundee) wins a free kick in the defensive half.
Foul by Stefan Johansen (Celtic).
Foul by Paul McGowan (Dundee).
Stefan Johansen (Celtic) wins a free kick on the left wing.
Attempt missed. Leigh Griffiths (Celtic) left footed shot from the left side of the box is close, but misses to the left.
Substitution, Celtic. John Guidetti replaces James Forrest.
Attempt missed. Anthony Stokes (Celtic) right footed shot from the centre of the box is high and wide to the right.