Peter MacDonald scored the only goal of the game as Dundee climbed to the top of the Scottish Championship with a 1-0 win over Alloa.
The visitors made a strong start to the game but Alloa defended brilliantly to prevent Dee from taking an early lead.
The Wasps then enjoyed a good spell of pressure at the end of the first half but they could not make their dominance count and it remained goalless at the break.
Dundee took the lead in the 68th minute when MacDonald got on the end of Martin Boyle's cross to head in from close range.
The visitors were reduced to 10 men in stoppage time when Iain Davidson saw red for violent conduct, but they held on to seal all three points.