In-demand striker Gary Hooper scored twice as Celtic won 4-1 at home to Hearts to retain their nine-point SPL advantage.
Neil Lennon confirmed on Friday he had rejected an offer, reportedly around £5m, from Norwich for the 24-year-old Englishman.
Hooper showed why he is attracting attention from south of the border when he slid in an Adam Matthews cross in the second minute for his 19th goal of the season.
Georgios Samaras added a second 10 minutes later but after Jason Holt pulled a goal back in the 68th minute, there was a nervy spell for the home side which only ended five minutes from time when Hooper grabbed a third, before substitute Lassad Nouioui, on for Matthews, grabbed a fourth in added time.
For the early opener, right-back Matthews raced up the wing and got the break of the ball as he attempted a one-two before driving into the box and squaring for Hooper to slide in from a couple of yards out.
The Tynecastle side looked all over the place and there was no surprise when Celtic doubled their lead 10 minutes later.
Again, the danger came down the Jambos' left-hand side. Midfielder Kris Commons pushed his way past Kevin McHattie and turned debutant Danny Wilson before his shot was parried by keeper Jamie MacDonald out to Samaras, who tapped into an empty net.
It looked like a Celtic goal-fest was on the cards but Hearts stabilised, to an extent, while the champions slackened off a bit.
Early in the second half, Hooper had the ball in the net from a Kris Commons cross but was ruled offside.
On the hour mark, with the Parkhead side in complete control, skipper Scott Brown headed a Matthews cross over the bar from eight yards and moments later Hooper set up Joe Ledley, whose drive from 10 yards was well saved by MacDonald for a corner, which was defended.
Five minutes later Jamie Walker again made a chance for himself when he broke past Celtic defender Mikael Lustig before making his way into the Parkhead box but his shot went high over the bar.
Moments after Beram Kayal replaced Ledley, the visitors found themselves back in the game when Jason Holt burst through the middle and unleashed a drive which deflected off Lustig and spun past Lukasz Zaluska.
A game that had been a stroll for the home side took on an edge but in the 85th minute, following determined work by Scott Brown, the ball fell to Hooper and he slammed it low past MacDonald.
Lassad made it four as the game nudged into added time when he converted a cross from Emilio Izaguirre.