Labour gained from SNP in a Glasgow City Council by-election just two weeks ahead of the Scottish Parliament contest in the knife-edge Dunfermline constituency.
Candidate John Kane won at Govan last night on a big swing, in the latest of a disappointing run of results for nationalists since last October's announcement of the independence referendum - now less than a year away.
The SNP's only comfort was that its vote share was down by just 1.5% but this was probably due to the absence this time of several high-scoring minor party runners from 2012.
John Flanagan, standing under the banner of No Bedroom Tax - No Welfare Cuts came third in the field of 14 candidates.
If the movement in Glasgow was to be repeated at Dunfermline on October 24, Labour would win the former SNP seat in a landslide.
A Labour recovery was already under way in last year's Scottish council elections compared with the 2011 Holyrood polls.
In the case of Dunfermline, this amounted to a 9.4% swing to the party from SNP on the basis of first count figures for four Fife Council wards covering the overwhelming majority of the constituency.
The party vote share totals were: Lab 9,484 (43.8%); SNP 5,814 (26.9%), Lib Dem 3,341 (14.4%); C 1,457 (7.2%); Others 1,457 (6.7%).
The constituency also includes 8% of a further ward where Labour was comfortably ahead.
Some voters will have two ballot papers on October 24 as there is a Fife Council by-election in Dunfermline South ward on the same day as the Holyrood contest.
RESULTS: Glasgow City - Govan: First count Lab 2055, SNP 1424, No Bedroom Tax 446, C 215, Ukip 113, Green 112, Ind 103, Lib Dem 73, Christian Party 60, Ind 52, Communist Party of Britain 35, Solidarity 28, Britannica Party 19, Scottish Democratic Alliance 1. (May 2012 - First count Lab 1727, SNP 1460, No description 644, Glasgow First 603, Lab 504, SNP 443, Glasgow First 398, SNP 356, Green 229, C 219, Scottish Unionist Party 143, Lib Dem 87, Solidarity 60, Pirate Party 51. Elected - Lab 2, SNP 1, Glasgow First 1). Lab gain from SNP. Swing 6.8% SNP to Lab.
The SNP's vote share fell 8.4% at Tweeddale West, Scottish Borders Council, which had a daytime count.
The Tories were boosted by easily holding the seat when they might have lost out because of the vagaries of the electoral system.
The single transferable vote method used in multi-member wards effectively becomes the alternative vote system in a by-election when only one seat is at stake.
This could have been expected to favour the Liberal Democrats, who comfortably led in votes cast in the ward in last year's main council polls.
RESULT: Scottish Borders Council - Tweeddale West: First count: C 1155, Lib Dem 677, SNP 359, Borders Party 228, Lab 203, Ind 43, Ukip 43. (May 2012 - First count Lib Dem 919, C 885, SNP 780, Lab 336, Lib Dem 334, Borders Party 333. Elected - Lib Dem 1, C 1, SNP 1). C hold. Swing 13.9% Lib Dem to C.