Jermain Defoe ended Spurs' eight-match winless run, and Blackburn's revival, with a first-half strike. The forward latched on to Ledley King's through ball and drilled a left-foot volley into the top left corner.
Blackburn failed to punish Spurs' poor defending after the break, with Jon Stead wasting a free header.
Andy Cole also went close with an overhead kick after Anthony Gardner's error, while Spurs' Robbie Keane headed against the underside of the crossbar.
The out-of-sorts Gardner did not make the most of his chance to impress watching England boss Sven-Goran Eriksson.
But the young defender was shown some sympathy by Blackburn, whose profligacy in front of goal matched his errors.
It was, perhaps, typical of two teams who have flirted dangerously with relegation this season.
Blackburn, though, came into the game on the back of four successive wins while Spurs had recorded one victory in 11.
And in the match programme, Tottenham chairman Daniel Levy labelled the club's season as "unacceptable", describing the team's form as "appalling".
But there was plenty of quality about Defoe's goal - his sixth since joining the club in January.
The strike may have had route-one origins, but the finish was sublime as Defoe drilled a half-volley past Peter Enckelman.
A disorganised defence has been Spurs' Achilles heel all season, and the inexperienced pairing of Gardner and King were exposed frequently.
The lively Stead went close on a number of occasions and Spurs had goalkeeper Kasey Keller to thank for his solid display.
But the 21-year-old Stead should have done better when set up by Cole after Gardner was far too casual inside his own box.
However, Spurs were much better coming forward and Keane and Defoe were causing the equally fragile Blackburn backline plenty of problems.
Keane came closest to underlining a much-improved Spurs display in the second half but his header came back off the bar.
Defender Christian Ziege, who had replaced the injured Mauricio Taricco after just 13 minutes, also threatened.
His goal-bound effort was cleared off the line by Michael Gray, and Enckelman made a smart stop to stop Defoe scoring a second.
