The match, in which Wales were crowned Grand Slam champions with a euphoric 29-12 victory, attracted a 26.9% share during the second half at 4.45pm, according to unofficial overnight figures. The first half of the match pulled in 5.2m viewers and a 30.3% share at 4.45pm.
Earlier in the afternoon, England's 33-10 win over Ireland brought in 4.5m viewers and a 33.2% share at 2.45pm.
Prior to the England game, Scotland's 23-10 defeat by Italy was watched by 2.5m viewers and a 24.9% at 12.30pm.
The audience figures demonstrate the huge pulling power of live televised sporting events at a time when the BBC is courting controversy following reports it is lining up a big money bid to snatch Champions League rights away from ITV and Sky.
Despite the popularity of the rugby, ITV1 earned a respectable audience for the first qualifying race of the Formula 1 season.
'F1: Australian Grand Prix Qualifying' netted 1.7m viewers and a 15.6% share at 1.15pm on Saturday afternoon, as viewers tuned in to British driver Lewis Hamilton beginning his second season in F1.
This article was first published on brandrepublic.com