Leaders Dundee saw their three-match winning sequence come to an abrupt end at Dens Park as Mark Burchill, one of their former players, scored the only goal in Livingston's 1-0 victory.
The home defence left him unguarded in the 11th minute and he headed what proved to be the only goal past Kyle Letheren.
Ryan Conroy should have equalised before half-time, but shot straight at Darren Jamieson and late on Declan Gallagher steered a header wide of target from only a handful of yards out.
Hamilton moved to within a point of the summit, but were hardly convincing in their 0-0 draw at Falkirk.
The Lanarkshire side had the better of the few chances created in a rather barren game, Ali Crawford having a first-half effort cleared off the line by Will Vaulks and Mickael Antoine-Curier missing the target from six yards early in the second half.
Garry O'Connor, playing his first match for over a year, lasted the full 90 minutes as bottom club Morton fought out a 0-0 draw against Raith Rovers at Cappielow. The result gave the Greenock side their first point under new manager Kenny Shiels.
O'Connor had the ball in the net at one stage, but was judged offside, leaving the ex-Scotland striker aggrieved.
In contrast, there was no shortage of goals at Central Park as Dumbarton eased their relegation concerns with a 4-2 win over Cowdenbeath. Mitch Megginson netted a double after Cowdenbeath had got off to a flier through Kyle Miller in the third minute.
Colin Nish equalised within a minute before Megginson gave Dumbarton the lead midway through the half with a wonderful strike from distance.
Jamie Stevenson equalised in the 27th minute after a mistake by Stephen Grindlay, but Dumbarton won it in the second half with two identical goals, firstly from Chris Kane and then Megginson with his second.
Queen of the South saw off Alloa 3-1 at Palmerston and manager Paul Hartley's frustrations boiled over late on when he was sent to the stand for dissent.
Michael Paton broke the deadlock in 29 minutes after a clever back-heel from Paul Burns, Gavin Reilly added the second before half-time and Derek Lyle clinched it early in the second half. Ross Caldwell hit Alloa's consolation.