It was a tale of two halves in Perth as Aberdeen mounted a second-half recovery to earn a share of the spoils from their trip to St Johnstone.
But quite how the Dons could be so Jekyll and Hyde in the space of 90 minutes is a mystery.
Lethargic in the first half, the Dons were aggressive and direct in the second. Had they found that form earlier they surely would have taken three points.
Saints made their first set-piece chance count in the 14th minute.
Liam Craig’s corner was met by David McMillan, the midfielder running away from marker Shay Logan to beat Joe Lewis with a near-post header.
The Saints caused the Dons problems down the flanks in an end-to-end opening and the stretched Aberdeen backline almost found themselves 2-0 down in the 19th minute as Drey Wright beat Max Lowe before delivering a low cross which Andy Considine diverted wide.
While Saints were finding the gaps the Dons found clear-cut chances few and far between. It took them until the 35th minute to create a real chance, Logan’s ball into the box finding Stevie May who fired at Zander Clark.
A lack of movement and quality in the final third left the Dons with nothing to aim for and Saints dealt comfortably with the visitors’ Plan B, which seemed to be long throw-ins from Logan towards Scott McKenna and Considine.
It was grim stuff, and a look at the manager’s threadbare bench offered little suggestions as to how to change things at half-time.
Saints created little either but, having established a one-goal lead, they at least had something to dig hold on to.
Aberdeen needed inspiration and McInnes turned to Sam Cosgrove, the centre-forward replacing Chris Forrester for the second half.
It took 35 seconds for the change to bring some urgency, with Cosgrove’s lay-off finding McGinn whose curling shot was turned away for a corner by Clark.
Aberdeen had found a threat which had been sorely absent in the first half and a quick corner almost brought an equaliser with Gary Mackay-Steven’s shot cleared off the line by Jason Kerr.
Saints had a penalty appeal dismissed when substitute Ross Callachan went to ground after jumping over the advancing Lewis. There was no contact from the Dons goalkeeper.
The second half display from the Dons had everything that was missing in the opening 45 minutes, and Mackay-Steven forced another save from Clark before the goalkeeper was called into action again seconds later to turn Cosgrove’s header past the post.
Dom Ball and Bruce Anderson were sent on as McInnes looked to keep the pressure on the Saints goal, and within seconds of their arrival the Dons were level.
Mackay-Steven was tripped on the edge of the box by Blair Alston and from the resulting free-kick McGinn curled the ball over the wall past Clark for a deserved equaliser.
Having worked so hard to get back on level terms the Dons had Lewis to thank for keeping the score at 1-1 as he made a superb block to deny Alston.