Linlithgow Rose never looked in danger as they strolled to victory over Cumbernauld United and it was a similar story at Duncansfield where Camelon Juniors were surprisingly convincing winners over Kilsyth Rangers.
But Bo’ness United saw their miserable run against Ayrshire sides continue in dramatic fashion as Troon came from behind to win with two goals in the closing 10 minutes.
Rossvale were comprehensive 5-0 winners at Lanark United while early goals in each half sank Carluke Rovers at Dundee North End.
Dunipace and Falkirk Juniors found the going hard away to former winners, both going down 4-1 to Arthurlie and Hurlford United respectively.
Three Fife sides - Kennoway Star Hearts, Glenrothes and Tayport - face replays but Dundonald Bluebell are out despite twice leading at Cumnock
Pollok were easy winners over Royal Albert at Newlandsfield.
Carnoustie Panmure’s match with Livingston United was a victim of the weather.
Linlithgow Rose 5 Cumbernauld United 0
It took Rose until just before the half-hour mark to make the breakthrough, Colin Leiper netting the opener.
Tommy Coyne doubled Rose’s lead eight minutes from the break and an own goal five minutes later virtually finished United off.
Coyne got his second and Rose’s fourth three minutes into the second half and Colin Strickland made it 5-0 six minutes later.
Kilsyth Rangers 1 Camelon 4
Camelon got off to the perfect start when Jamie Glasgow put then ahead from the penalty spot in the first minute.
Worse was to follow for Kilsyth when Camelon were awarded another penalty and Glasgow doubled the visitors’ advantage.
Grant then virtually finished the game as a contest with a third just before half-time.
Gary Wright made it 4-0 early in the second half before Kilsyth pulled one back.
Troon 2 Bo’ness United 1
Bo’ness got a great early boost when Michael Gemmell put them ahead in just five minutes and that was all that separated the sides at the break.
It looked as if a single goal might be enough for Bo’ness, but then the roof fell in.
The visitors were reduced to 10 men after 79 minutes when Ian Nimmo was red carded and Troon took full advantage to level through Morgan Brown.
And worse was to follow for Allan McGonigal’s side as Chris McKnight got a dramatic winner in injury-time to end Bo’ness cup hopes for another year.
Lanark United 0 Rossvale 5
Rossvale took the lead in 28 minutes, Chris McQuade netting from the penalty spot.
Six minutes later it was looking good for Martin Lauchlan’s side when Jason McKay doubled their advantage and Fraser Team put the outcome beyond any real doubt with a third on the stroke of half-time.
Alex Cassells got Rossvale’s fourth from the penalty spot 12 minutes into the second half and Team made it 5-0 with 15 minutes to go.
Dundee North End 2 Carluke Rovers 0
Carluke fell behind to an early goal and it stayed that way until half-time.
Unfortunately for Rovers the second half started in similar fashion to the first, an early goal doubling the Taysiders’ advantage.
A disappointing day was rounded off for Carluke when Mark Weir and Chick McCole were both sent off.
Arthurlie 4 Dunipace 1
Dunipace shocked the home side with the opening goal midway through the first half.
However their lead didn’t last long as Ryan McGregor quickly levelled for the Barrhead side and a Gary Smith free-kick gave them a 2-1 advantage at half-time.
Smith got his second from the penalty spot early in the second half and Chris Dallas made it 4-1 in the closing stages.
Hurlford United 4 Falkirk Juniors 1
Hurlford, cup winners two seasons ago, broke the deadlock just after the half-hour mark and added a second before half-time.
A third goal early in the second half left the visitors with a mountain to climb and although James McAteer pulled one back the home side restored their three-goal advantage.
Royal Albert 1 Pollok 4 (at Pollok)
Pollok opened the scoring in nine minutes, Allan MacKenzie finishing off a fine move, and Chris Walker headed a second in 29 minutes.
David Winters put Pollok’s place in the fourth round beyond doubt with a third goal in 61 minutes and Steven Higgins made it 4-0 12 minutes later.
Pollok were reduced to 10 men when Walker was sent off for a second yellow card and Royal Albert then reduced the deficit to 4-1 before they too had a player red carded.
St Roch’s 1 Kennoway Star Hearts 1
In an exciting first half Hearts had a penalty claim turned down and St Roch’s missed a glorious chance, but the match remained goalless at the break.
Just when it seemed as if a stalemate was looming Kennoway broke the deadlock through Kyle Wilson, but the Glasgow side rallied to earn a replay with a late equaliser
Glenrothes 2 Rosyth Recreation 2
Glenrothes opened the scoring in 24 minutes through midfielder Scott Napier but the visitors hit back to level four minutes later.
John Martin put the home side back in front in the 36th minute but once more Rosyth came back to level from the penalty spot three minutes from half-time.
Tayport 0 Muirkirk 0
Tayport were unable to break down their Ayrshire opponents in a match played 25 years to the day since Muirkirk’s last visit.
The three-time winners will now have to try to progress the hard way by winning the replay away from home.
Cumnock 3 Dundonald Bluebell 2
Bluebell broke the deadlock in 13 minutes but Ross McNeil got the Ayrshire side back on level terms 12 minutes later.
Dundonald regained the lead shortly but back came Cumnock with Kieren Wood making it 2-2 just before the interval.
Cumnock took the lead for the first time through Aiden Malone early in the second period and held on to end Bluebell’s hopes.