Griffiths helps Celtic go six clear
Dundee United 1Celtic 4
Leigh Griffith broke through the half-century of goals mark for Celtic as the Hoops swept away Ladbrokes Premiership bottom side Dundee United in a convincing 4-1 win Tannadice.
The Parkhead striker took 21 minutes to take his tally to 50 in just 60 starts - the fastest Celt to reach that landmark since Charlie Nicholas in the early 1980s - before defender Jozo Simunovic doubled the visitors' lead with his first counter for the impressive champions.
United forward Simon Murray reduced the deficit just after the half-hour mark but it was to prove only a consolation as the free-scoring Scotland international grabbed his second three minutes after the restart to make it 51 all-in before midfielder Kris Commons added a fourth.
The comprehensive victory took Celtic six points clear of Aberdeen at the top of the table and left Mixu Paatelainen's men battered, bruised and still 11 points adrift of second-bottom Kilmarnock.
On a freezing night on Tayside, the Parkhead men started with some purpose with former United midfielder Stuart Armstrong and Commons both having decent drives just missing the target.
There was no surprise that Celtic took the lead nor with the identity of the scorer.
When United defender Gavin Gunning slipped outside his box while seemingly ready to clear the former Wolves attacker took advantage.
He raced through to drill the ball under Japanese keeper Eiji Kawashima for his 23rd goal of the season before taking off his top to reveal a shirt with the number 50 on it for which he was booked by referee Bobby Madden.
The second came in the 27th minute when Commons' free-kick from the left was headed in all too easily by Simunovic for his first Celtic goal since joining the club in the summer from Dinamo Zagreb.
It was all too easy for the slick-moving league leaders but four minutes later a good United move ended with John Souttar striding forward to release Murray who poked it past keeper Craig Gordon, back after suspension.
But the goal did not signal a comeback, instead it inspired Deila's side to turn on the style.
Kawashima, who looked nervy in the first-half, produced a fine save from a powerfully-struck Commons' free-kick early in the second-half.
However, he had no chance when stand-in skipper Mikael Lustig picked out Griffiths with a cross, the Hoops striker burying a right-footed shot from the edge of the box.
Griffiths, understandably, went looking for his hat-trick but it was Commons who got the next goal in the 56th minute, spectacularly volleying an Armstrong cross high into the net from six yards.