EDINBURGH : Wings Mack Hansen and James Lowe scored a try each for Ireland as flyhalf Johnny Sexton became the joint leading scorer in Six Nations history following a pulsating 22-7 victory over Scotland at Murrayfield on Sunday.Replacement number eight Jack Conan scored Ireland's third try as they turned up the heat in the second half despite the loss of both hookers to injury, leading to flanker Josh van der Flier throwing in at the line-out and three props in the front row of the scrum.Scotland were in the game at halftime as they trailed 8-7 having scored a try through centre Huw Jones, which will give them some confidence heading into the Rugby World Cup where they face Ireland and South Africa in their pool with only two teams to advance to the quarter-finals.Ireland, who have claimed the Triple Crown and have their sights now set on a Grand Slam, lead the Six Nations table with 19 points from four games, four ahead of second-placed France.