Saints produced a stirring second-half fightback as they secured a 25-17 Aviva Premiership success against struggling London Irish at Franklin's Gardens.
After an error-strewn first-half display, the black, green and gold headed in at half-time 14-3 down.
Alex Lewington pounced twice, taking advantage of Saints' sluggishness to put his team in control.
But Irish were stunned early in the second half as George North, Rob Horne and Mike Haywood all scored within 10 minutes of the restart.
Piers Francis landed a timely drop goal to banish any lingering fears of a London Irish win, and ex-Saint Greig Tonks missed a late penalty to ensure the away side left with nothing.
Saints had gone into the game on the back of a disappointing 32-9 defeat at Bath and they were stunned early on as some poor passing gifted London Irish an opening try.
Luther Burrell wasn't able to gather the ball in time and Saracens-bound wing Lewington pounced, kicking the ball ahead and diving on it to score.
Tonks landed the conversion with aplomb and London Irish then did some superb defensive work, shutting down a lengthy spell of Saints pressure and winning a penalty.
Still the home side came, desperately probing for an opening, with a nice line from Campese Ma'afu causing Irish problems.
But the men in blue were standing tall, scrambling well and they got a let-off when Francis saw his penalty attempt rebound off the post to safety.
And Saints were soon punished further as Irish grabbed another opportunistic score.
A kick ahead caught North napping and Lewington beat him to the ball, diving on it to claim the try.
Tonks converted and it was 14-0 to Irish with 25 minutes of the match gone.
Francis made amends for his earlier penalty miss to narrow the deficit with an effort from the tee, but Irish were not deterred and they continued to grow in confidence.
A sign of their belief came just before the break as the kicked a penalty to the corner, pushing for their third try.
But Christian Day pouched the lineout and ensured the gap would remain at 11 points at the break.
Saints were clearly given a stern talking to at half-time as they came out flying, scoring inside the first minute of the second period.
Burrell sent North over in the corner, with both men making amends for their earlier errors.
Francis converted to cut the deficit to just four points and Saints were soon ahead as Burrell picked up another assist, sending Horne over in the corner.
Francis needed treatment before taking the conversion, and he was to send it just wide of the posts.
But he got another bite at the cherry soon after, landing a conversion after try-hungry hooker Haywood had scored from a lineout drive that Irish never threatened to stop.
Irish then sent on a whole new front row and Scott Steele at scrum-half, and Tonks landed a penalty to give them a foothold in the game once again.
But Francis cancelled that effort out with a clever drop goal eight minutes from time.
Tonks missed the chance to pick up a losing bonus point for his team as the fly-half fluffed a penalty attempt.
And Saints saw out the final minute to secure the comeback success.
Saints: Tuala; North, Horne, Burrell, Foden; Francis, Groom (Reinach 67); Ma'afu (van Wyk 65), Haywood, Brookes (Ford-Robinson 22); Ratuniyarawa, Day (c) (Ribbans 53); Gibson, Brüssow (Wood 65), Harrison.
London Irish: Marshall; Cokanasiga (Tikoirotuma 72), Fowlie, McLean, Lewington; Tonks, van Zyl (Steele 50); Franks (Elrington 50), Paice (Porecki 50), Hoskins (Du Plessis 50); van der Merwe (c), Paulo (de Chaves 65); Botha, Northcote-Green (Gilsenan 74), Treviranus.
Referee: Ian Tempest