Caley Thistle had found the net in their previous 25 matches, with their SPL games averaging four goals a game, but they found St Johnstone difficult to break down despite having two one-on-ones in the opening stages, neither straightforward.
Gregory Tade had a similar chance saved for the hosts, who also saw David McCracken's header cleared off the line.
SPL top goalscorer Billy McKay had the opportunity to add to his tally in the second minute when he got the better of Frazer Wright on the left wing and bore down on goal, but the angle proved too tight and the Caley forward curled just beyond the far post.
McKay's lay-off then set up Andrew Shinnie to run through on goal. The Scotland international got past a defender but Alan Mannus was quickly off his line and blocked the shot with his legs.
St Johnstone's first effort on goal came from Liam Craig's powerful free-kick from 30 yards but it was straight at Antonio Reguero, who punched away.
Saints came close in the 41st minute when McCracken met Craig's deep corner but Owain Tudur Jones headed off the line.
Saints changed their strikeforce in the 59th minute when Rowan Vine replaced Steven MacLean and the substitute soon played Tade through, but the former Inverness forward could not steer his shot past Reguero, who blocked with his feet.
Tade almost made amends with a persistent run That allowed Dave MacKay a strike at goal with Reguero stranded, but Gary Warren was quickly out to block and Murray Davidson headed wide after Craig returned the ball into the box.
Conor Pepper and Philip Roberts came on for Inverness late on and the latter's header from a corner was flicked just over by McKay.
- Sports & Recreation
- Gregory Tade
- St Johnstone