Celtic manager Neil Lennon insists there's more magic to come from his team after Ryan Christie's late goal booked the holders a Scottish Cup semi-final date with Aberdeen at the expense of Tommy Wright's St Johnstone in Perth.
Lennon's men are still in pursuit of a fourth consecutive domestic treble after the 1-0 victory while the other last-four showdown sees Hearts take on Hibernian in an Edinburgh derby.
The semi-finals will be played at Hampden Park on April 11 and 12.
"The next obstacle in front of us is a really tough Aberdeen team," said Lennon. "But if you're going to win the Cup you've got to beat everything that's put in front of you.
"I think there's more to come from this team, I've said they can get better and that's what we'll look to do. Europe's finished unfortunately, but we've still got a lot of trophies to play for."
Wright said: "I thought we deserved a replay. We were excellent and created a lot of good opportunities, particularly in the first half."
Hearts overcame Rangers 1-0 on Saturday night to knock them out of the Scottish Cup in a fiery quarter-final at Tynecastle and it was a result which left Gers boss Steven Gerrard contemplating his future, saying he needed to do "serious thinking in the next 24, 48 hours".
Alfredo Morelos missed the defeat for disciplinary reasons after he was allowed to return to his Colombian homeland last week but reported back 24 hours late.
"He's failed to report to training on Thursday, which means he's missed a lot of the preparation," said Gerrard.