Motherwell took a commanding half-time lead at St Johnstone with goals from John Spencer, Derek Adams and Derek Townsley at McDiarmid Park in a thrilling encounter.
But the home side were denied on a number of occasions by the excellent Andy Goram in the visitors' goal.
John Paul McBride almost opened the scoring for St Johnstone in the opening minutes with a deft ball over Motherwell keeper Goram.
Saints midfielder Paul Kane played a quick free-kick to McBride who attempted his chip from the edge of the area, but the ball dropped just wide of the post.
Garry Bollan also forced a great save seconds later with a blistering free-kick.
But it was the visitors who took the lead when Spencer dummied Kane from Townsley's pass before shooting over Alan Main from 30 yards.
Saints were almost back in the game five minutes later when Jim Weir glanced a Mohamed Sylla corner just wide.
McBride was involved again in the 20th minute when he found Keigan Parker on the edge of the box.
The young striker fed a great ball to Sylla who was chasing him on the right-hand side of the area, but his drive was just wide of Goram's right-hand post.
McBride and Parker combined again on the edge of the area, but the one-two move broke down and the ball bounced off referee David Somers to be cleared by Greg Strong.
Darren Dods became the first man to be booked in the 29th minute for a foul on Kevin Twaddle.
Saints were threatening to come back into the game before Adams increased the visitors' lead five minutes from the break.
Spencer played the ball wide to the right where Townsley was waiting. The winger played the ball into the danger area and Adams picked his spot for the second goal.
However Motherwell were not finished and Adams turned provider two minutes from the break when his perfect corner was headed home by Townsley.
But tempers were frayed in the final minute of the half when both Sylla and Adams were booked after a touchline flare-up.