John Barnes had to endure another trying night before Celtic came through with an injury-time winner against Dundee in their League Cup quarter-final at Parkhead last night. Morten Wieghorst's headed goal for a 1-0 win saved the Celtic head coach further embarrassment.

Barnes, under pressure after his side suffered five losses in their previous eight games, lost the red-carded Stephane Mahe in the 43rd minute after the Frenchman tangled with Dundee's Eddie Annand. Mahe appeared to aim a retaliatory kick after being fouled by Annand and found himself instantly dismissed.

In scenes reminiscent of his sending-off in last May's Old Firm game, Mahe had to be led from the field by his colleagues as he protested his innocence. Annand only received a yellow card for his part in the incident. Referee Hugh Dallas was again the man dishing out the cards.

Reduced to 10 men, Celtic sacrificed Ian Wright for defensive midfielder Petrov at half-time with the Bulgarian determined to impress after Craig Burley's £3 million sale to Derby.

Dundee failed to capitalise on their numerical advantage, but extra-time still appeared a certainty before Mark Burchill's cross picked out Wieghorst for a stunning finale. Substitute Burchill raced down the left and crossed for Wieghorst to place a looping header into the net for a last-gasp victory.

The green side of Glasgow will also have taken some cheer from Aberdeen's defeat of Rangers. Bottom of the table Aberdeen won through at Pittodrie with a last-gasp goal in extra time from midfielder Andy Dow.

With both sides looking towards a penalty shoot-out substitute Kevin Rutkiewicz's shot was charged down into the patch of Dow who hammered past Rangers goalkeeper Thomas Myhre from close range to put Aberdeen into the semi-final.

Dundee United's David Hannah was sent off in disgrace for manhandling the referee in their quarter-final against Motherwell, but his team-mates still managed to clinch a semi-final place with a 3-2 victory at Tannadice.

Referee Dougie McDonald awarded a penalty against Hannah for pulling down Motherwell substitute John Spencer with the match at 3-1. Hannah pushed the match official in a fit of frustration, was then sent off, and could now find himself facing a disrepute charge.