Tories gained from Labour in the latest local by-elections just a day after a massive slump in a London contest.
Conservative Gill Cartwright returns to Darlington Council on a big swing, less than a year since losing at Harrowgate Hill.
Tories came close to taking a second seat in the borough at Hurworth where Liberal Democrats held on by 38 votes.
However, Wednesday's result in north London's Barnet Borough must be of concern to Conservatives ahead of the capital's elections on May 3 - despite the opinion poll lead for their mayoral runner Boris Johnson.
Labour's elections machine was successful in getting its supporters out at East Finchley. The party candidate took nearly 70% of the votes it polled in 2010 on the same day as the general election - despite a drop in turnout to 28%.
A similar performance London-wide on May 3 could enable it to defy the polls.
Darlington Borough - Harrowgate Hill: C 694, Lab 607, Lib Dem 142, Ukip 95, England First 47. (May 2011 - Three seats Lab 1261, 959, 910, C 863, 590, 554). C gain from Lab. Swing 13.6% Lab to C.
Darlington Borough - Hurworth: Lib Dem 474, C 436, Lab 144, Ukip 31. (May 2011 - Two seats Lib Dem 886, 568, C 505, 386, Lab 175, 175). Lib Dem hold. Swing 8.6% Lib Dem to C.
Newark and Sherwood District - Lowdham: C 787, Lib Dem 534, Lab 117, Ind 91. (May 2011 - Two seats C unopposed). C hold.
From Wednesday: Barnet London Borough - East Finchley: Lab 2117, C 543, Lib Dem 461. (May 2010 - Three seats Lab 3315, 2931, 2868, C 1994, 1855, Lib Dem 1735, C 1723, Lib Dem 1397, 1237, Green 652, 588, 477). Lab hold. Swing 16.6% C to Lab.