Wales took advantage of Scotland's lack of discipline to move to the top of the Six Nations standings with a 27-13 win in Cardiff on Sunday.

In that time the Scots conceded 24 points and try as they might, the deficit was always going to be too big to make up.

In the tight first half  Greig Laidlaw and Leigh Halfpenny exchanged penalties to leave the teams deadlocked at the break.

Two crucial errors inside the first five minutes of the second half - which cost Scotland 10 points and reduced them to 14 players - blew the game wide open.

First Chris Cusiter made an almighty mess-up from the restart and from the resulting attacking line-out Wales eventually scored the opening try - when big Alex Cuthbert brushed aside the rookie flyhalf, Laidlaw.

That conversion and a penalty minutes later - when Nick da Luca was yellow carded for a professional foul - by Halfpenny turned a 3-all half-time score into a 13-3 lead.

Even though Laidlaw managed to pull three points back, the Welsh made their numerical advantage count and Halfpenny scored a well-worked try in the 52nd minute and converted it to push the lead out to 20-6.

It got even worse for the Scots. Two minutes before Da Luca returned to the play Rory Lamont joined him in the sin bin after yet another professional foul.

And within minutes Halfpenny went over for his second try, from a scrum and a blindside move against the badly exposed Scottish defence. The conversion made it 27-6 - a 24-point blitz in 15 minutes.

Scotland showed great heart to keep battling on and a Laidlaw try in the 65th minute, after ferocious forward raids by the Scots, gave the visitors some hope.

Even though Wales were reduced to 14 men in the last five minutes - when prop Gethin Jenkins was sin-binned for repeated offences at the breakdown - the Scots simply did not have enough gas in the tank to make up the 14-point deficit.

The scorers:

For Wales:
Tries: Cuthbert, Halfpenny 2
Cons: Halfpenny 3
Pens: Halfpenny 2

For Scotland:
Try: Laidlaw
Con: Laidlaw
Pens: Laidlaw 2

Yellow cards: Nick da Luca (Scotland, 45 - professional foul, tackling the man without the ball), Rory Lamont (Scotland, 54 - professional foul, tackled player from offside), Gethin Jenkins (Wales, 76 - repeated offences at the breakdown)

Teams:

Wales: 15 Leigh Halfpenny, 14 Alex Cuthbert, 13 Jonathan Davies, 12 Jamie Roberts, 11 George North, 10 Rhys Priestland, 9 Mike Phillips, 8 Toby Faletau, 7 Sam Warburton (captain), 6 Dan Lydiate, 5 Ian Evans, 4 Ryan Jones, 3 Adam Jones, 2 Huw Bennett, 1 Gethin Jenkins.
Replacements: 16 Ken Owens, 17 Paul James, 18 Lou Reed, 19 Andy Powell, 20 Lloyd Williams, 21 James Hook, 22 Scott Williams.

Scotland: 15 Rory Lamont, 14 Lee Jones, 13 Nick De Luca, 12 Sean Lamont, 11 Max Evans, 10 Greig Laidlaw, 9 Chris Cusiter, 8 David Denton, 7 Ross Rennie, 6 Alasdair Strokosch, 5 Jim Hamilton, 4 Richie Gray, 3 Geoff Cross, 2 Ross Ford (captain), 1 Allan Jacobsen.
Replacements: 16 Scott Lawson, 17 Ed Kalman, 18 Alastair Kellock, 19 John Barclay, 20 Mike Blair, 21 Duncan Weir, 22 Stuart Hogg.

Referee: Romain Poite (France)
Assistant referees: Peter Fitzgibbon (Ireland), Simon McDowell (Ireland)
TMO: Giulio De Santis (Italy)