Georgios Samaras' first domestic goal of the season put Celtic back on top of the Scottish Premier League after an entertaining victory over Hearts.
The visitors had goalkeeper Jamie MacDonald stretchered off after a collision with Charlie Mulgrew.
Replacement Peter Enckelman was slow to react as Samaras' low drive put Celtic ahead after 34 minutes.
Both sides had chances to add to the scoreline, but it was the Glasgow side who were always in control.
Marius Zaliukas and Darren Barr look concerned for Jamie MacDonald
And Celtic's fifth straight victory - they are now unbeaten in their last six outings - lifted them two points clear of Hibernian with a game in hand.
Mulgrew continued in Celtic's midfield, where James Forrest replaced the injured Scott Brown, after his fine display in the 3-2 Champions League win over Spartak Moscow and forced a fine early block from MacDonald.
The versatile Scotland international played a one-two with Gary Hooper, who had a quiet 100th appearance for the club, on the edge of the penalty area but fired his low drive against the outrushing goalkeeper.
MacDonald's participation was to end in the 14th minute after bravely punching clear under a Mulgrew challenge from an Emilio Izaguirre cross.
Forrest just failed to turn Kris Commons' first-time effort into the net at the back post as MacDonald and Mulgrew were left motionless on the pitch and the signal went out for former St Johnstone goalkeeper Peter Enckelman to prepare for his debut from the bench.
Hearts' first threat came from an unlikely source as Darren Barr, pushed up into midfield as Andy Webster replaced Scott Robinson in the starting line-up, fired powerfully but straight at new England squad goalkeeper Fraser Forster.
Andrew Driver robbed a casual Kelvin Wilson and, when the winger played the ball into the path of Callum Paterson, the young striker poked it wide as he slid in from 10 yards.
Celtic responded and unmarked Moscow match-winner Samaras sent a side-footed volley on to the outside of the post from eight yards following a Commons cross.
Mulgrew had obviously not recovered fully from his earlier head collision and was replaced with Joe Ledley after 32 minutes.
However, that did not knock Celtic out of their stride and they immediately went ahead when Commons played Samaras through and the striker's low drive powered under the hapless Enckelman.
The goalkeeper was nearly caught out again by a quickly-taken Commons free-kick that curled wide of the far post.
Hearts' Ryan Stevenson twice teased the Celtic uprights from long range then Mehdi Taouil forced Forster to turn a thundering 20-yard drive over the crossbar.
Man-of-the-match Commons and Samaras both went close either side of the half-time break as Celtic looked to kill the game.
Hearts lost Paterson, replaced with John Sutton, after 52 minutes following a hefty challenge from behind by Wilson that somehow went unpenalised by referee Craig Thomson.
Commons and Izaguirre took turns to lead Ryan McGowan a merry dance, but their efforts from tight angles failed to find the net.
Samaras sent a header just over, while Forrest and Commons both tested the nervous Enckelman, but Celtic's midweek exertions appeared to be catching up on them.
However, as Celtic ran out of steam, Hearts were out of ideas and were unable to make the most of their best opportunity when Driver fired wide in stoppage time.
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