Caley Thistle came from a goal behind to force a replay with a 1-1 draw against St Mirren.
Inverness were off colour in the first-half, and fell behind to Marc McAusland’s opener on 17 minutes.
However, a positive response from John Hughes’ side forced an equaliser from Josh Meekings on 64 minutes, and although the Caley Jags dominated the remaining minutes they could not find a way through, with the tie going to a replay at the Caledonian Stadium on Tuesday.
Caley Thistle were forced to make two changes, with top scorer Marley Watkins and midfielder Greg Tansey suspended having been sent off in the 5-0 defeat against Dundee United in last year’s competition.
That meant returns to the side for Ross Draper, back from a one-match suspension of his own, and Nick Ross who made his first start of the season.
Under pressure Saints manager Tommy Craig rang the changes after being boosted by the return of several key players, with Stephen Thompson, Isaac Osbourne, John McGinn and James Marwood the quartet drafted into the side, in place of Adam Drury, Ross Caldwell and youngsters Jack Baird and Stephen Mallan.
Neither side were able to stamp their authority on the game in the opening exchanges, however St Mirren capitalised on poor defending to take the lead on 17 minutes.
After Thompson mis-hit his volley from a corner, the ball was returned from wide right by Jason Naismith, with defender McAusland left unmarked to steer into the net from five yards.
With chances for both sides few and far between in the remaining first-half minutes, Inverness knew they had to respond brightly in the second-half in order to remain in the cup.
They forced the issue of an equaliser, with Ryan Christie shooting just over from 25 yards, however they grabbed the equaliser from a corner on 64 minutes.
In a crowded penalty box Draper was twice denied by the post, before Christie’s shot was also blocked on the line, but the Buddies defence couldn’t hold out any longer when the ball came to Josh Meekings to drill a powerful strike into Mark Ridgers’ bottom left-hand corner from just inside the box.
David Raven, Billy Mckay and Aaron Doran all blasted over late efforts, however the sides could not be separated.