Man-of-the match James Forrest helped himself to a brace in Saturday's SPL clash at Celtic Park with further goals from fellow midfielders Joe Ledley and Ki Sung-yueng as the disappointing Steelmen were dismantled with ease.
Neil Lennon's men will travel to Spain with confidence for what is sure to be more difficult task as they remained one point behind SPL leaders Rangers, whom they meet in the first Old Firm derby of the season at Ibrox next Sunday.
All in all, it was a good afternoon's work for the Parkhead side who at no point looked like they may be troubled.
New signing Badr El-Kaddouri, on loan from Dinamo Kiev, took over from left-back Charlie Mulgrew who moved in to the centre of defence at the expense of Daniel Majstorovic, who dropped out altogether.
Right-back Adam Matthews replaced injured Cha Du-ri, while skipper Scott Brown failed a fitness test on his ankle, his place taken by Ledley.
It was a tepid start by the home side, skippered for the day by midfielder Beram Kayal, but they still went ahead after only eight minutes through Forrest.
An impressive move by the Parkhead side saw Gary Hooper link up with strike-partner Anthony Stokes and, when the Irishman's pass split the Well defence, Forrest guided the ball past Well keeper Darren Randolph from 12 yards with some assurance.
The visitors responded and in the 16th minute left-back Steven Hammell worked a one-two with midfielder Keith Lasley inside the Celtic box, but lone-striker Michael Higdon turned after taking the cut-back and drove wide.
However, in the 27th minute, after Randolph had flapped at a Mulgrew corner, the Fir Park side almost fell further behind.
As the ball bounced around inside the box Hooper tried an overhead kick which came off the bar before Fir Park captain Stephen Craigan cleared with Stokes waiting to head the ball in to the empty net.
A minute later Randolph made up for his error with a decent save from Forrest's low drive from the edge of the box.
Just before the half-hour mark Chris Humphrey replaced Shaun Hutchinson who looked to have injured himself and there was soon more woe for Stuart McCall's side.
In the 33rd minute the Steelmen failed to defend properly again and, when Stokes slipped the ball through to Ledley, the Wales midfielder quickly slammed the ball past Randolph.
Motherwell midfielder Steve Jennings was then booked for a rash challenge on Hooper with the Celtic striker also seeing yellow for his reaction.
Three minutes from the break Forrest threaded his way to the edge of the Well box again, but sent his shot inches wide of the post before Ledley forced a save from Randolph with a drive from distance.
Good odds were available at half-time for a Motherwell comeback and they would have increased further two minutes into the second half had defender Tim Clancy's wayward pass back, which fooled Randolph, gone in to his own net instead of just past the post.
The Lanarkshire side survived the corner and, when Ki combined with Mulgrew minutes later, they were again lucky that no Celtic player was on the end of the cross which sped across the goal begging to be knocked home.
It seemed all too easy for Celtic and on the hour mark Forrest ran on to a clever flick from Hooper at the edge of the visitors' box, but did not connect with his shot properly and the ball ran past the far post.
However, it was all over in the 67th minute when Ki made it 3-0, the South Korean hammering in a drive from 25 yards after Ledley laid the ball in to his path after taking a Hooper pass.
Lennon's other new signing, Mohamed Bangura, the 22-year-old African striker brought in from AIK Stockholm, came on for Stokes to a great reception from the home fans.
Kayal drove just wide from distance before Forrest grabbed his second in the 73rd minute, running through the dispirited Motherwell defence before knocking the ball past Randolph.
There was a late shout for a Celtic penalty when Clancy clashed with Forrest inside the box but referee Alan Muir was having none of it.
But by then the damage was done.