A SLUGGISH, hung-over Celtic side slumped to a 1-0 defeat to St Johnstone at Celtic Park, a defeat that saw them blow the chance to open up a nine-point lead at the top of the table.

A second-half Danny Swanson volley gave the Perth side all three points in a game in which Celtic never quite found their rhythm.

Clearly suffering from the effects of a week in the San Siro followed by a home win over Aberdeen two days later, Celtic struggled to find any kind of fluency against a disciplined and organised Saints side.

Stuart Armstrong and Gary Mackay-Steven engineered the bulk of Celtic's early chances, although Anthony Stokes came close in the opening period with one attempt that curled just wide of the target.

Eight minutes after the break, however, it was St Johnstone who took the lead when Celtic failed to properly clear a David Wotherspoon corner and Swanson sunk a strike that will be among the goals of the season package.

In a bid to inject some energy and creativity into the side, Mackay-Steven made way for James Forrest while Nir Bitton took over from Stokes.

Efe Ambrose came close to levelling with a header from a Stefan Johansen corner but St Johnstone too could have had more; Chris Millar blasted over from inside the box while Steven MacLean came closing to adding to the scoreline.

Celtic predictably threw everything forward in the latter stages but couldn't find a way through a resolute Saints side.