British and Irish Lions forward Paul O'Connell has praised his side's dominance at set pieces following their comprehensive 59-8 win over the Barbarians this afternoon.

O'Connell captained the side in the opening match of their summer tour, scoring one of the eight tries that helped the Lions cruise to a comfortable win under conditions that saw humidity levels reach 94%.

The Irish lock believes that their success at the lineout and scrum was key to their performance, but admits that it is hard to draw any conclusions from the match.

"I'm delighted to get the win and win really well. The conditions, that was the big worry for everybody, but we wore them down in the first half and the points came fairly easily in the second half," O'Connell told Sky Sports News.

"Set-piece is such a massive part of the game. If you turn over the line out you get possession back. If you turn over the scrum you get a penalty, three points for 50 metres, so set piece and the scrum set a massive platform for us today. They had nothing to play off really and we had a lot to play off, got a lot of ground and got a lot of points off them.

"The conditions were very hard. Obviously the Barbarians are a great side but maybe mentally they aren't in the same place as we were so it's very hard to tell [what it means]."

The Lions' next match comes against Western Force on Wednesday, June 5.