Greg Docherty volleyed Accies in front after Alexandre D'Acol's header was blocked following a free-kick.
Saints goalkeeper Zander Clark saved well to deny Docherty a second, then at the other end Danny Swanson hit the bar.
Liam Craig equalised in the final 10 minutes when he pounced on the rebound from Blair Alston's shot.
St Johnstone rang the changes in the wake of their Betfred League Cup defeat by Aberdeen but were forced into another switch early in the game.
Richard Foster was injured with just a minute gone and could not continue. He was replaced by Aaron Comrie.
All that on top of the fact they were missing Steven McLean, who does not play on synthetic surfaces.
The incentive was there for both clubs - a win would have taken Saints second - but you would not have believed that given the opening spell.
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The goalmouth thrills were slow in coming although Graham Cummins was left totally unmarked on the end of a free-kick from the left side, only to screw his header beyond the right-hand post of the Accies keeper.
Remi Matthews, though, was not quite as comfortable with a low shot from Craig which he spilled, only to be rescued by a team-mate.
But then work from the training ground undid St Johnstone.
Ali Crawford floated a free-kick for D'Acol to head back across the goal. A Saints head won the second ball but it fell only for Docherty, who lashed it into the net. It was his first goal of the season.
And moments later Docherty was the hero again, clearing off the line a goalbound header from Joe Shaughnessy. Now the game was alive.
The players had to endure pounding rain in the second half but it encouraged pace on the plastic pitch and Swanson capitalised with flashes of class, including a double nutmeg which set up a Saints chance.
Accies, too, knew how to play the conditions. Dougie Imrie zipped a shot across the goal which was a hair's breadth away from a touch from Eamonn Brophy on the slide.
The game ebbed and flowed until its death, but you did feel a Saints equaliser was coming.
Alston nearly grabbed it, but Matthews denied him with a spectacular save, only for the rebound to be driven into the net from the edge of the box with great composure.
Both sides went in hunt of a late winner at the end of a second half which was both entertaining and competitive, but a draw was just about right.
Hamilton's Martin Canning: "There wasn't a lot in it and in the second half they had us pinned back a bit.
"But it's been the story of the season for us so far; we have a great opportunity to go 2-0 up and we don't take it.
"I feel like I'm repeating myself. The guys are putting in a lot of work but we are not putting the ball in the net enough."
St Johnstone's Tommy Wright: "I didn't think we deserved to be 1-0 down at half time and we did enough in the second half to at least earn the draw.
"It was important that we freshened things up after Thursday [League Cup defeat at Aberdeen] and the strength of the squad allowed me to do that.
"It was an entertaining game and I'm pleased with the way we came back to get the point."
Match ends, Hamilton Academical 1, St. Johnstone 1.
Second Half ends, Hamilton Academical 1, St. Johnstone 1.
Corner,  Hamilton Academical. Conceded by Joe Shaughnessy.
Corner,  St. Johnstone. Conceded by Ali Crawford.
Attempt saved. Christopher Kane (St. Johnstone) right footed shot from the right side of the box is saved in the bottom right corner.
Ali Crawford (Hamilton Academical) is shown the yellow card for a bad foul.
Danny Swanson (St. Johnstone) wins a free kick in the attacking half.
Foul by Ali Crawford (Hamilton Academical).
Grant Gillespie (Hamilton Academical) wins a free kick in the defensive half.
Foul by Brian Easton (St. Johnstone).
Attempt missed. Christopher Kane (St. Johnstone) left footed shot from the right side of the box misses to the left.
Foul by Danny Seaborne (Hamilton Academical).
Christopher Kane (St. Johnstone) wins a free kick on the right wing.
Attempt blocked. Liam Craig (St. Johnstone) left footed shot from the right side of the box is blocked.
Corner,  St. Johnstone. Conceded by Greg Docherty.
Attempt missed. Greg Docherty (Hamilton Academical) right footed shot from the right side of the box is too high.
Danny Seaborne (Hamilton Academical) wins a free kick in the attacking half.
Foul by Christopher Kane (St. Johnstone).
Corner,  Hamilton Academical. Conceded by Brian Easton.
Corner,  Hamilton Academical. Conceded by Zander Clark.
Attempt saved. Dougie Imrie (Hamilton Academical) right footed shot from outside the box is saved in the top centre of the goal.
Attempt saved. Blair Alston (St. Johnstone) right footed shot from outside the box is saved in the centre of the goal.
Goal!  Hamilton Academical 1, St. Johnstone 1. Liam Craig (St. Johnstone) left footed shot from outside the box to the bottom right corner.
Attempt missed. Murray Davidson (St. Johnstone) right footed shot from outside the box is close, but misses the top left corner.
Attempt saved. Joe Shaughnessy (St. Johnstone) right footed shot from the centre of the box is saved in the bottom right corner.
Danny Seaborne (Hamilton Academical) is shown the yellow card for a bad foul.
Foul by Danny Seaborne (Hamilton Academical).
Christopher Kane (St. Johnstone) wins a free kick in the defensive half.
Substitution, Hamilton Academical. Rakish Bingham replaces Eamonn Brophy.
Christopher Kane (St. Johnstone) wins a free kick in the defensive half.
Foul by Danny Seaborne (Hamilton Academical).
Foul by Christopher Kane (St. Johnstone).
Dougie Imrie (Hamilton Academical) wins a free kick on the right wing.
Foul by Louis Longridge (Hamilton Academical).
Brian Easton (St. Johnstone) wins a free kick in the defensive half.
Substitution, St. Johnstone. Christopher Kane replaces Graham Cummins.
Attempt missed. Eamonn Brophy (Hamilton Academical) header from the centre of the box is close, but misses the top right corner.
Attempt missed. Danny Swanson (St. Johnstone) right footed shot from outside the box is just a bit too high.
Darian MacKinnon (Hamilton Academical) is shown the yellow card for a bad foul.
Foul by Darian MacKinnon (Hamilton Academical).
Hamilton moved off the bottom of the Scottish Premiership but had to settle for a point at home to St Johnstone.