St Johnstone opened up a two-goal lead in the first half of the first leg, but Reece McAlear's second-half brace has left the tie delicately poised ahead of the return fixture at McDiarmid Park.
Match preview
St Johnstone were extremely comfortable in the first half of Friday's first leg, and their dominance brought two goals, with Shaun Rooney's header being followed by an effort from Melker Hallberg, as the visitors opened up a 2-0 advantage inside the first 24 minutes in Inverness.
However, Callum Davidson's side were ultimately pegged back in the second half, as McAlear's late brace ensured that Inverness would have a fighting chance heading into Monday's second leg.
St Johnstone finished 11th in the Scottish Premiership, boasting a record of eight wins, 11 draws and 19 defeats from their 38 matches to collect 35 points.
The Saints finished fifth in last season's Scottish Premiership, in addition to winning a cup double, but there is no getting away from the fact that it has been a tough season for the club, who are bidding to avoid being relegated to the second tier of Scottish football.
St Johnstone are unbeaten against Inverness since August 2016, which should hand them confidence heading into this match, and they won 3-0 when the two teams last locked horns at McDiarmid Park.
Inverness finished third in the regular Scottish Championship season, collecting 59 points from their 36 matches, boasting a record of 16 wins, 11 draws and nine defeats during a solid campaign.
Billy Dodds's side have since beaten Patrick Thistle and Arbroath in the playoffs to advance to this stage, and they are now just one game away from securing a return to the Scottish Premiership.
Inverness have been absent from the top flight of Scottish football since the 2016-17 campaign, spending each of the last four seasons in the second tier, but their performance in the second half of the first leg on Friday will hand them confidence ahead of a difficult contest at McDiarmid Park.
Caley Thistle, who won the Scottish Cup in 2015, are actually unbeaten in all competitions since a 2-1 reverse at Queen of the South on April 19.
The visitors will certainly be the underdogs heading into the second leg, but head coach Dodds said after Friday's match that his players now realised that they were "good enough" to compete at this level.
St Johnstone Scottish Premiership Playoffs form:
St Johnstone form (all competitions):
Inverness Caledonian Thistle Scottish Premiership Playoffs form:
Inverness Caledonian Thistle form (all competitions):
Team News
St Johnstone will again be without Tony Gallacher, Chris Kane, David Wotherspoon and Craig Bryson through injury.
The Scottish Premiership side did not pick up any fresh concerns in the first leg, though, so it would not be a surprise to see the same starting XI take to the field.
Glenn Middleton and Callum Hendry are set to feature in the final third of the field, meaning that Steven May will likely have to accept a spot on the bench once again.
Inverness boss Dodds made two half-time changes in the first leg, with Logan Chalmers and Austin Samuels both being introduced, and the pair could now come into the starting side for this match.
Scott Allardice is also an option for change, but Dodds is unlikely to make too many alterations, with his side not picking up any fresh injury concerns.
A 3-5-2 formation will see two-goal McAlear play in midfield once again, while Billy McKay will retain his position in the final third of the field.
Danny Devine and Wallace Duffy are back from suspension, though, with the pair pushing to return to the starting XI for the second leg on Monday night.
St Johnstone possible starting lineup:
Clark; Cleary, Gordon, McCart; Rooney, Hallberg, Davidson, MacPherson, Brown; Hendy, Middleton
Inverness Caledonian Thistle possible starting lineup:
Ridgers; Broadfoot, Duffy, Devine; Carson, Chalmers, Hyde, McAlear, Harper; Samuels, McKay
We say: St Johnstone 2-1 Inverness Caledonian Thistle
Inverness have given themselves a real chance ahead of the second leg, but we are finding it difficult to back the visitors here. Indeed, St Johnstone's superior quality across the park should ultimately shine through to ensure that they are present in the Scottish Premiership next term.