SAINTS coach Keiron Cunningham blamed his side's poor ruck defence as the main factor behind their 41-16 humbling at home to title rivals Leeds.

The Rhinos cashed in on some loose play to rip Saints apart up the middle to leave them chasing the game at the interval.

Cunningham also defended his decision to start with star scrum half Luke Walsh on the bench - after seeing the Australian play maker transform the game following his introduction at the break.

After watching his side slump to a fourth loss in five games Cunningham explained: "I thought our ruck D and marker play was extremely poor.

"As a result we became a victim of our own errors. You can't give a side as good as Leeds that many chances around the ruck.

"They have a great nine and a lot of good support players that take advantage. The resilience and scramble is always good from Saints but our ruck D let us down massively.

"And the thing is we came out in the second half after speaking about it and looked a different side. If we had done that in the first half then I'm sure it would have been a completely different game."

Saints trailed 28-6 at half time, but the re-jigging of the line-up - with Walsh coming in for Jon Wilkin at seven with the Saints skipper going into the pack - saw a more organised and dynamic team in the second half.

Cunningham added: "It was always the plan to introduce Luke back the way we have and I had to hold my nerve on him.

"He played 25 minutes last week, a half this and will start next week.

"That is how it was always going to be and I knew he would make a difference as he is a great seven.

"To be honest I thought our attack looked good. We didn't have issue in yardage or good ball and we rolled Leeds down the field. Perhaps we did that a little too easily and the boys may have taken it for granted and became soft around the rucks because of it.

"That said, Leeds are a great side and can strike from anywhere. There were times we were down the field and they went full length from an intercept. That is what good sides do and you have to take your opportunities."