Soccer - Scottish Round-Up:Rangers' hopes of a domestic treble were shattered as they crashed out of the Scottish Cup quarter-final courtesy of a David Robertson's last-gasp winner for Dundee United. In the league Celtic were thumped 4-0 away to St Mirren.
Robertson struck in the final minute of the quarter-final replay to secure United a meeting with Raith Rovers in the last four of the competition.
Rangers' hopes of retaining the Premier League may have been boosted by tonight’s Celtic result but a lacklustre performance in Tayside means the Ibrox club will be disappointed after losing the prospect of a clean sweep this season.
Celtic's faint hopes of catching Rangers at the top of the Premier League were all but ended with their first league defeat at St Mirren in 21 years.
In the most dramatic of nights in Paisley, double strikes by Andy Dorman and Steven Thomson ripped the visitors apart in the astonishing rout.
The Parkhead side remain 10 points behind their Ibrox rivals who have two games in hand.
In the night's other game, Hamilton moved further out of relegation danger after a slick attacking display earned them a well-deserved 2-1 victory at Kilmarnock.
Mickael Antoine-Curier and Simon Mensing netted within five minutes midway through the first half as Accies moved eight points away from the bottom of the league.
The Lanarkshire side missed several chances to put the game out of sight before Chris Maguire pulled one back, but they survived the remaining 13 minutes without serious danger.
Selected Cross-Channel Results
Scottish Premier League
Kilmarnock 1 Hamilton 2
St Mirren 4 Celtic 0
Scottish Cup Quarter-final replay
Dundee Utd 1 Rangers 0
Premier League
Aston Villa 1 Sunderland 1
Blackburn 2 Birmingham 1
Man City 0 Everton 2
Portsmouth 0 Chelsea 5
FA Cup Quarter-final replay
Tottenham 3 Fulham 1