Ben Foden showed England head coach Eddie Jones what he is missing as the full-back scored a last-gasp try to lead Northampton to a 27-23 victory at The Stoop and inflicting a first home defeat on Harlequins this season.
In a frantic first half the visitors took the lead three times, centre Luther Burrell also demonstrating his talents to Jones as he set up a try for Christian Day and scored another.
The two tries and the boot of Stephen Myler gave Northampton a 17-14 lead at half-time, the hosts getting on the scoreboard through tries for George Merrick and Ross Chisholm, with fly-half Nick Evans kicking both conversions.
In a tighter second half Evans added two penalties to JJ Hanrahan's one before the Kiwi's replacement Ben Botica looked to have won the hosts the game with a 72nd-minute three-pointer.
But Botica soon went from hero to villain as with time up he failed to find touch and Saints got the ball into Foden's hand and he won them the game for their first Premiership win since New Year's Day.
Myler capitalised on Northampton's quick start and put the visitors ahead inside five minutes with an easily converted penalty.
But Harlequins put seven points on the board with their first real attack of the game in the moments later as some good hands presented Merrick with a simple opportunity to cross the line and Evans added the extras.
Myler was gifted the opportunity to add another three for Saints after Quins were penalised for holding on but his effort hit the post in blustery conditions.
However, an excellent burst from Burrell saw him tear through Quins' defensive unit and unselfishly offload the ball to Day who ran home unopposed before Myler made no mistake with the conversion.
Chisholm handed the lead back to Quins in the 23rd minute as he received the ball 10 yards from the line and charged over to claim his third Premiership try of the season, Evans once again converted with ease.
But the first-half action did not stop there and on the half hour mark Burrell put Saints ahead for the third time in the game after being set up by centre partner Harry Mallinder, Myler successfully kicking his second conversion.
And the half ended on an even more sour note for the hosts as Tito Tebaldi was sent to the sin bin for a deliberate knock on, with Saints leading 17-14.
Harlequins made light work of being a man down however as Evans scored his first penalty of the game three minutes into the second half to level proceedings.
And the number 10 continued his excellent kicking form to give the hosts the lead with a penalty from straight in front of the posts after Northampton were penalised for a deliberate knock on.
The home side dominated the first 15 minutes of the second half and were yards away from extending their lead on several occasions, but resilient defending from Saints kept the gap to three points.
Tom Wood was sent to the sin bin with 14 minutes to play for bringing down the Quins maul with them inches away from crossing the line.
But the Saints appeared to be spurred on by the loss of Wood and drew level with a Hanrahan penalty.
The hosts immediately regained their lead through a Botica penalty after Saints were penalised for holding on.
But with the 80 minutes up Saints had one chance left to win the game and some patient build up allowed Foden space and he faked to pass before bursting through the last line of defence to win the game, with Hanrahan adding the conversion.