Robson scored after Vennegoor of Hesselink won the penalty
Celtic got their defence of the Scottish Premier League title off to a winning start thanks to a controversial Barry Robson penalty against St Mirren.
The Buddies had matched their more illustrious opponents, with a Billy Mehmet drive striking a post.
But referee Eddie Smith ruled that Jan Vennegoor of Hesselink had been held back by defender Will Haining when the striker was through on goal.
Haining was sent off and Robson's spot kick spun over the line off the keeper.
The widow of the late Celtic coach Tommy Burns, who died from cancer in May, had raised the championship flag ahead of kick-off as Celtic made an emotional start to their title defence.
Rosemary Burns was aided by team captain Stephen McManus, who had recovered from a groin problem to take his place in a now-familiar starting line-up from which injured midfielder Shunsuke Nakamura was the only absentee.
St Mirren manager Gus MacPherson selected just Mehmet up front, a defensive formation perhaps dictated as much by the absence through injury of the influential Andy Dorman, Gary Mason and Craig Dargo as a desire to frustrate their hosts.
But, although Celtic started with a bit of flag-waving gusto, it was the visitors who were first to find the target, with Garry Brady and Stephen McGinn firing long-range efforts at Artur Boruc that the goalkeeper nevertheless dealt with fairly comfortably.
Celtic were also being restricted to long range apart from a head flick by Scott McDonald that ended up going over the crossbar from an Andreas Hinkel cross.
The first half closed with the Glasgow side having given the 57,000 crowd little to cheer following the pre-match euphoria.
Haining and Vennegoor of Hesselink joined hands at Celtic Park
There was some concern in the St Mirren dressing-room over the fitness of Tom Brighton, making his competitive debut for the club along with Jack Ross, but the former Clyde and Millwall striker emerged again after the break.
It was the Celtic defence who were doing the worrying as the second half started, Stephen O'Donnell setting up Mehmet on the edge of the box and the striker's side-footed drive would have found the net had Boruc's outstretched hand not turned the ball on to a post.
Celtic responded immediately and Gary Caldwell ought to have done better than head straight at Howard from 12 yards after being found unmarked at a free-kick.
Vennegoor of Hesselink had half-hearted claims for a penalty waved away after a chase with Howard to a slack Ross pass-back.
But Celtic's Dutch striker won the spot kick that led to the deadlock being broken after 62 minutes.
Vennegoor of Hesselink pounced when the Buddies defence failed to deal with a long ball through the heart of the defence and poked the ball wide of the post under pressure from Haining.
Referee Smith decided that the striker had been tugged from behind by the defender, who was shown a red card, although television pictures suggested that Vennegoor of Hesselink had been doing his own share of holding.
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