Dundee 0 Celtic 1
Celtic reclaimed top spot in the Bank of Scotland Premier League after a hard-fought battle at Dens Park in which Bobo Balde's first-half strike proved the decisive factor.
Martin O'Neill however was forced to watch in horror as his Champions League injury crisis deepened.
Last season's UEFA Cup finalists were fortunate to take the points as calamitous referee Dougie McDonald dubiously awarded them a free-kick in the lead up to the only goal.
The official also infuriated the Celtic boss when he controversially showed Didier Agathe a straight red card after he had won the ball fairly.
O'Neill's mood was also not helped by the sight of Stephen Crainey hobbling off just days before they open their European campaign against Bayern Munich in the Olympic Stadium.
His squad is already being tested to the maximum after skipper Paul Lambert joined injured quartet Johan Mjallby, Joos Valgaeren, Ulrik Laursen and Steve Guppy and the suspended Chris Sutton on the sidelines after being ruled out for at least six weeks.
After a nervous start, Celtic controversially took the lead on eight minutes against the run of play.
McDonald harshly penalised Gavin Rae for a challenge on Alan Thompson near the touchline, but from Crainey's free-kick Bobo Balde towered above the static Dundee defence to head into the back of the net off the underside of the bar.
Worryingly for Dundee, who were looking for their first win here against Celtic in 15 years, the visitors stepped up a couple of gears and had a good chance to double their lead in the 16th minute.
John Hartson, starting his first game for Celtic since the victory at Ibrox in April, did well in the centre and his poor pass was directed into the path of Henrik Larsson, but the Swede's was comfortably saved by Julian Speroni.
But O'Neill's injury worries deepened in the 20th minute when Crainey was forced to hobble off after coming out worse from a late challenge on Rae.
He was subsequently replaced by promising Irish midfield talent Liam Miller, but Celtic suffered more misery five minutes later when they were controversially reduced to 10 men.
Lovell sent Nacho Novo clean through with a superb pass, but Didier Agathe sprinted back and appeared to take the ball away from the falling Dundee man. To Celtic's amazement the referee first awarded a free-kick to the home side and then brandished the red card.
O'Neill took every opportunity thereafter to hurl abuse at the under-fire official as John Hartson's protests were waved away after he was wrestled to the ground.
Novo was causing problems in their new-look three-man defence and his cross should have brought better in the 37th minute, but Lovell headed over from six yards.
Varga could have eased the tension before the break, but he headed Thompson's corner just wide from close range.
As the side's emerged for the second-half, O'Neill looked slightly calmer after trying to confront the referee as they made their way off the pitch.
But his emotions were almost eased even further two minutes after the restart, but Petrov was just unable to reach Miller's inviting ball across the face of goal.
The hard-working Hartson was sacrificed as Momo Sylla came on and signalled for Larsson to operate in midfield.
But the referee went card crazy again and booked Thompson for dissent and Lennon for gesturing at the crowd.
Lovell's name was the next to be taken for tripping McNamara, but O'Neill was relieved to see Larsson return to action after sustaining a heavy challenge late on.
The Swede was not moving freely as the referee blew his final whistle which would suggest that the next few nights may be sleepless for O'Neill.