Wales coach Warren Gatland said none of his team was "blowing" in the changing room, and all felt comfortable. He and his assistants urged the team to put on a show. But a different Scotland came out for the second half, and Wales had to survive an onslaught to prevail 18-11. Wales returns home to play defending champion Ireland for the Grand Slam next weekend in Cardiff, relieved to get out of Edinburgh still unbeaten after four rounds.
"Any team that's won a Grand Slam, and I think back even to last year with Ireland and that Johnny Sexton drop goal, you look back at certain games and know you've had a little bit of luck," said Gatland, on the verge of his third Grand Slam.
Scotland virtually owned the second half, playing with all of the ball, forcing penalties, and pinning Wales down. Grant Gilchrist was held up over the line, then Darcy Graham finished a brilliant backs move, and Scotland trailed only 15-11 with 22 minutes to go and their crowd roaring them on.
The revived Scots, who have beaten Wales only once in 11 years, threatened an upset until each threat was ruined by errors; a spill or bad pass or turnover. Wales' renowned defense bent but didn't break, having to make 138 tackles in the second half after 66 in the first.
A compelling match finished with Scotland, frustrated and patched together, back in its 22 for the first time since the end of the first half, and Wales flyhalf-cum-fullback Gareth Anscombe kicking a second penalty to complete their record-extending 13th straight win.
Despite worries at home concerning an overhaul of its clubs, Wales next Saturday will be in Cardiff going for its first Grand Slam since 2012, and a first Six Nations crown since 2013. Gatland said the club turmoil hasn't helped the team.
"Players are on the phone home, texting, going to meetings and talking to people in clubs. There's a lot of emotion involved," he said. "But they got on with the job and I'm proud of them for digging deep."
All of Wales' seven previous tries in the tournament came after halftime, but wing Josh Adams was over after just 13 minutes. Jonathan Davies gave him the overlap with a forward pass, and Adams shimmied past Blair Kinghorn to score behind the posts.
Davies scored the second after a coolly composed 24-phase buildup that was reminiscent of Wales' match-turning 35-phase try against England two weeks ago. The buildup, dominated by the forwards, featured two big crashes into the defense by Davies' midfield partner Hadleigh Parkes.
Wales almost finished the half with more points, but an Anscombe penalty into the sun rebounded off the left post, Parkes regathered, and Adams knocked on to end the chance. That was Wales' first handling error of the half, at which point Scotland was game as usual but outclassed.
Then, suddenly, Wales became the punching bag in the second half. Gilchrist was held up over the line by Parkes, and then a rolling maul drew in the Welsh defense, a Finn Russell inside pass to Byron McGuigan put the replacement wing in space, and replacement fullback Adam Hastings sent Graham diving into the right corner.
Scotland was alive and kicking with more than a quarter left, but the injury-hit backline was creaking, and they couldn't finish off the stubborn Welsh. Balls were knocked on or passes dropped, soft penalties given up, and an 18-phase play finished with a turnover. Wales gratefully accepted each relief, and a 12th win over the Scots in their last 13 matchups.
"We're massively disappointed," captain Stuart McInally said. "We had chances to win and weren't accurate enough. "We cost ourselves defensively in the first half, gave them a couple of soft tries. And we threw everything at them in the second half but couldn't bring them down."
Scotland has lost three in a row, and faces a daunting finale next weekend at Twickenham, where it hasn't won in 36 years.
More AP sports: https://apnews.com/apf-sports and https://twitter.com/AP_Sports