Wales boss Wayne Pivac hailed a stunning performance by Louis Rees-Zammit after the Gloucester wing’s try double secured a thrilling 25-24 Guinness Six Nations victory over Scotland.Scotland were looking to build on last week’s historic Twickenham win over England and got off to the perfect start at Murrayfield with tries from Darcy Graham and Stuart Hogg.But their hopes were wrecked when Zander Fagerson was sent off for a dangerous clear-out in the second-half, and Wales ruthlessly exploited their numerical advantage.