St Johnstone suffered a dramatic exit from the Premier Sports Cup after conceding a stoppage-time equaliser against East Fife, while Dundee United secured their place in the last 16 thanks to Montrose's surprise defeat to Spartans.
Montrose entered their final Group B fixture needing only a draw to finish top of the group, but the League One side fell to a 2-0 home defeat against League Two outfit Spartans, allowing Dundee United to advance.
St Johnstone's hopes of reaching the knockout rounds also ended in heartbreaking fashion.
A victory over East Fife would have given the Premiership side a chance of qualifying as one of the best runners-up, but Jack Healy's late equaliser denied them all three points.
The Fifers then claimed the bonus point in the penalty shootout to secure second place, while St Johnstone finished third behind Inverness Caledonian Thistle and East Fife.
Aberdeen, Ayr United, Kilmarnock, Ross County, Stenhousemuir, Dundee United and Inverness Caledonian Thistle all booked their places as group winners.
Dundee and Partick Thistle also progressed as two of the three best runners-up, with the final qualification places to be decided on Sunday.
St Mirren will top Group C if they avoid defeat at home to Dunfermline Athletic.
A Dunfermline victory would guarantee them qualification either as group winners or one of the best runners-up thanks to their superior goal difference.
Aberdeen wrapped up top spot with a convincing 3-0 victory over League Two side Kelty Hearts.
Kevin Nisbet opened the scoring from the penalty spot after just two minutes - his sixth goal of the group stage - before setting up Kjartan Kjartansson for the second.
Toyosi Olusanya completed the scoring shortly after halftime.
Queen's Park also ended their campaign on a high, defeating Queen of the South 3-1.
Michael Ruth converted an early penalty before Tyrece McDonnell doubled the lead.
Ben Johnstone briefly reduced the deficit, but Matthew Shiels restored the Championship side's two-goal cushion.
Montrose looked destined to top Group B until Spartans produced one of the surprises of the round.
James Craigen's early free-kick gave the visitors the lead before MacKenzie Ross sealed a famous 2-0 victory in the second half, ending Montrose's hopes of progressing.
Elsewhere, Arbroath defeated Stirling Albion 1-0 thanks to Ryan Dow's second-half strike.
Ross County comfortably secured first place in Group D with a commanding victory over Airdrieonians.
Jamie Lindsay, Jack Turner and new signing Lewis Jamieson all found the net as County continued their impressive campaign.
Dundee claimed a runners-up spot after defeating Clyde 4-0.
Alan Forrest broke the deadlock early in the second half before Simon Murray converted from the penalty spot and Simon Westley added two late goals.
Stenhousemuir emerged victorious from a tightly contested Group E after drawing 0-0 with Livingston before winning the penalty shootout to claim the bonus point.
The result proved decisive, as Livingston missed out on qualification as one of the best runners-up.
Forfar Athletic rounded off the group with a 3-1 victory over Brechin City, with Martin Rennie scoring twice and Scott Shepherd also on target.
Inverness Caledonian Thistle sealed first place in Group F thanks to Alfie Bavidge's early penalty in a 1-0 win over Greenock Morton.
Meanwhile, St Johnstone's campaign ended in frustration after Sam Stanton appeared to have secured victory with a stoppage-time goal against East Fife.
However, Jack Healy capitalised on a defensive mistake moments later to rescue a draw before East Fife claimed the penalty shootout bonus point, eliminating the Saints.
Ayr United secured top spot in Group G with an impressive win over Alloa Athletic, inspired by a standout performance from Dundee United loanee striker, who scored twice and set up Jamie Murphy.
Kieran Shanks also found the net as Ayr cruised to victory.
Although already eliminated, Falkirk finished with a win over Stranraer thanks to goals from Ryan Strain, Liam Henderson and Ben Parkinson.
Kilmarnock advanced from Group H despite another frustrating outing, drawing 0-0 with Peterhead before losing the penalty shootout.
The single point was enough to see Neil McCann's side finish one point clear of Hamilton Academical, who ended their campaign with an emphatic 5-0 victory over Elgin City, led by a brace from Stuart Bannigan.
