Brittain, who has been trying to persuade St Johnstone to tear up the pre-contract agreement he signed with the Perth club in January, levelled with expertly-taken penalties 14 minutes from the start and end of the game.
The Perth club have so far refused Brittain's request and the 29-year-old, who has cited family reasons for his change of heart, was jeered by some Saints fans and emphatically celebrated his second equaliser.
Steven MacLean and Murray Davidson both headed Saints in front, but the draw only really favoured Motherwell and Inverness, who occupy the two European places on offer behind champions Celtic.
Motherwell are now one win away from securing a Europa League spot while Caley Thistle have a four-point lead over St Johnstone with County a point further behind.
Both clubs failed in a joint bid to change the 4.05pm kick-off, which was scheduled for live coverage by BBC ALBA and only 2,444 fans turned out.
Those who did saw two sides going all out for victory and St Johnstone taking the lead inside six minutes with a route-one goal.
Goalkeeper Alan Mannus launched a huge kick upfield and Gregory Tade beat Grant Munro to the ball to head on. The County defence, which had Andre Hainault making his first start for the suspended Scott Boyd, was caught flat by MacLean's run and the striker looped a head over Michael Fraser.
Fraser was soon under pressure as he flapped at Tade's back-post header in a crowded goalmouth but Mehdi Abeid sliced the rebound wide.
The visitors were soon back in the game with the second of two parried Iain Vigurs shots leading to their first penalty.
Mannus spilled the effort back out to the edge of the box and Vigurs got to the ball just before Chris Millar, who brought the midfielder down.
Brittain stepped up to take the pressure spot-kick and showed impressive composure to place the ball just inside the right-hand post.
St Johnstone were next to threaten when Dave Mackay powered a 30-yard effort that Fraser parried to safety and the hosts regained the lead in the 25th minute after Munro had been booked for a foul on Davidson, who had returned from injury to replace the suspended Liam Craig.
Abeid drove in the free-kick from the right flank and Davidson rose near the penalty spot to guide the ball into the top corner.
Rowan Vine soon shot just wide from 20 yards and Fraser saved from Abeid from similar range but the Dingwall side continued to look dangerous too and Mannus tipped Paul Lawson's shot wide before pulling off a magnificent save two minutes from the interval.
The ball fell invitingly for Ivan Sproule 18 yards out and the winger produced a swerving volley that appeared destined for the far corner of the goal but Mannus threw himself to his right and got a fingertip to the ball to divert it wide.
Seconds after the restart, Fraser was quickly off his line to thwart Abeid, who soon got in behind the County defence again, but Tade could not connect with his driven cutback.
MacLean also flashed a header wide as St Johnstone looked comfortable, although County threatened when Vigurs released Steffen Wohlfarth only for the German to shoot wide of the near post.
The visitors lost their second left-back to injury when Branislav Micic, who had come on for Evangelos Ikonomou at half-time, saw his unconvincing debut ended after 25 minutes by a shoulder injury that he aggravated when bringing down Tade. Steven Ross came on and Vigurs dropped back as County moved to a 4-4-2.
They were level in the 76th minute after Tam Scobbie needlessly brought down Sproule, who had his back to goal on the bye-line, after Mannus had pushed away Brittain's powerful 20-yard drive.
The midfielder opted for the other side of the net as he sent Mannus the wrong way from the spot before celebrating in determined fashion in front of the visiting fans.
Both sides had chances for a winner. Fraser produced a point-blank save from Tade's header after an excellent delivery from Abeid and Scobbie got his team in trouble again with a short headed passback which Wohlfarth could only head wide.
- Sports & Recreation
- St Johnstone
- Alan Mannus