Hearts became the first team to progress to the semi-finals of the Scottish Cup with a thrilling 2-1 victory over Partick at Tynecastle.
Graham Rix's side took the lead after just six minutes, Edgares Jankauskas coolly heading in Paul Hartley's brilliant cross from the left, and it looked as if the SPL high-flyers were set for a comfortable afternoon
Their unheralded opponents gradually found their way back into the game though, and would have drawn level but for a stupendous save from Craig Gordon after Billy Gordon's fierce shot had taken a wicked deflection.
Hearts were given some breathing space when Lithuanian Deividas Cesnauskis scored a stunning second, cutting in from the left and unleashing an unstoppable drive from the edge of the area into the top corner (63).
Roman Bednar received a second yellow card for an embarrassing dive in the hope of earning a penalty, before Partick deservedly pulled a goal back.
Mark Roberts jinked his way past two defenders on the edge of the box, opened up his body and slotted in a quality finish (75).
Thistle poured forward in pursuit of an equaliser, but Hearts survived some anxious moments to book their place in the last four.
Hibernian joined their Edinburgh rivals in the next round after thrashing Falkirk 5-1 in the only all-SPL tie of the round.
Derek Riordan fired Hibs in front after just nine minutes, but they were then frustrated for nearly an hour until Garry O'Connor's strike (67) sparked a late flurry of goals.
Daniel McBreen (70) reduced the lead to 2-1, but clinical finishes from Ivan Sproule (74), Gary Caldwell (77) and Steven Fletcher (88) put some gloss on the scoreline as Falkirk tried to get back into the match.
Gretna, tipped by many to go all the way and lift the trophy, beat St Mirren 1-0 at Raydale Park, with Kenny Deuchar (73) grabbing the all-important goal.
In the day's final quarter final, Dundee and Hamilton will need a replay to separate them after playing out a goalless draw.