Northampton fly-half James Grayson has warned that his side must avoid "switching off" in games following their season-opening defeat at Sale.

They responded with three of their own but were unable to erase the deficit and went down 29-22 in the Premiership.

"In this league, if you switch off for 10 minutes, teams can rip you apart," Grayson told BBC Radio Northampton.

"We felt we applied a lot of pressure in the first half, we spent a lot of time in their 22 but didn't actually come away with any points, so that's a learning for next week.

"And in the second half, that 10-minute, maybe 15-minute, period, when we switched off really cost us - but that last 15 minutes is probably where we want to be and what we want to be doing to teams."

Saints took an early lead through Grayson's penalty and he later added two conversions in their strong finish to the game.

"To come back and scrape a (losing bonus) point, at the end of the season that one point might be quite important," he said.

"There's a lot of frustration, but (we have) momentum from that last 15 minutes. We'll build on that and we'll look at the bits we did poorly and we'll build on that as well."

Northampton's first home match of the campaign against London Irish has been switched from Friday to Saturday, with a 14:00 BST kick-off.

Saints won the corresponding game last season 23-21 and also triumphed 42-22 when the two teams met in round 21 at the Brentford Community Stadium.