Scotland go into half-time at Cardiff City Stadium 1-0 up thanks to a James Morrison strike in a game in which chances were plentiful but finishing was poor.
Much was made of Steven Fletcher's return to the Scotland team, but it was Gareth Bale who proved the immediate danger. After sending a dipping volley over the crossbar early on, the Tottenham winger went the closest by cutting inside from the right and curling a long-range effort just wide of the far post with Allan MacGregor beaten.
Joe Allen also posed a significant danger for the hosts, and came very close to breaking the deadlock when he robbed on the halfway line and allowed his team to spring a counter-attack, receiving the ball in the penalty area and cutting inside only to see his effort blocked by Alan Hutton.
Shortly afterwards, in a spell of dominance for the home side, Steve Morison really ought to have scored after collecting a cross from the right wing and despite having considerable freedom in the Scottish area, nodded wide of the far post with Allen MacGregor stranded.
After Morison's missed sitter, it was his almost-namesake who showed how to finish at the other end: Wales were made to pay a heavy price for their profligacy, along with some pretty poor defending after Steven Fletcher flicked on Allen MacGregor's goal-kick for the onrushing and untracked James Morrison to latch onto and finish coolly to put the Scots ahead with the most simple of route-one moves.
Wales looked rattled after conceding the goal, and their frustration was exemplified by Gareth Bale, blazing two terrible efforts from outside the area - one free-kick, and one centre from Joe Allen - well wide.
Towards the end of the half, Steven Fletcher had a chance to score on his return for the Scots and double their lead, but scuffed James Morrison's cross, resulting in a tame effort.
Wales had a brief scare when Aaron Ramsey appeared to be limping, but continued to play and received perhaps Wales' best chance of the half, receiving a cross in the area at high-speed but sending an awful effort high and wide.
For Scotland, the Morrison-Fletcher combination showed promise once again at the end of the half. Morrison really should've made it two-nil after a Steven Fletcher knockdown left him in an ocean of space on the edge of the hosts' area, but whacked his volley over the bar.