Rangers came into the match on the back of a 6-0 defeat at near neighbours Fulham but responded well, dominating the majority of the first period.
QPR's early momentum paid dividends as they took the lead in the 16th minute through Heidar Helguson's cross-cum-shot.
The striker's goal was the west Londoners' first at Loftus Road this season, but their joy was short-lived as Samba latched on to Jason Lowe's corner to put Kean's side level.
Goalbound: Chris Samba (second right) watches as his headed effort beats the QPR rearguard
MATCH FACTSQPR: Kenny, Young, Ferdinand, Hall, Traore, Derry, Faurlin, Wright-Phillips (Smith 83), Barton, Mackie (Taarabt 64), Helguson.Subs not used: Murphy, Orr, Bothroyd, Buzsaky, Puncheon.
Booked: Hall, Wright-Phillips, Traore.
Goal: Helguson 16.
Blackburn: Robinson, Salgado, Samba, Dann, Givet, Lowe, Petrovic, Nzonzi, Olsson, Hoilett, Roberts (Goodwillie 67). Subs not used: Bunn, Formica, Rochina, Yakubu, Vukcevic, Hanley.
Booked: Nzonzi, Lowe.
Goal: Samba 24.
Referee: Mark Clattenburg.
Both sides wasted chances to win the match in the second half, with results elsewhere putting Blackburn bottom of the league despite ending a two-match losing streak.
Jamie Mackie was named in the QPR starting line-up for the first time since suffering a double leg break against the same opponents. The 26-year-old was injured in a collision with Gael Givet in an FA Cup tie in January.
Mackie was one of three changes made by manager Neil Warnock, with Helguson and Armand Traore also included in the side.
Blackburn made three changes to the side that lost 4-0 to Manchester City, drafting in Jason Roberts, MichelSalgado and Martin Olsson.
QPR pressed from the off and, after Helguson came close to connecting with Traore's left-wing cross, Alejandro Faurlin blazed a long-range drive over.
Blackburn had a chance of their own at the other end in the 13th minute when Anton Ferdinand shinned an Olsson cross just over, before QPR broke the deadlock three minutes later.
After Helguson saw a header accidentally blocked by Rangers skipper Joey Barton, the 34-year-old chipped over a cross from the right that snuck in at the back post.
The agony and the ecstasy: Paul Robinson (left) and Jonas Olsson can do nothing to stop Heidar Helguson's (not pictured) looping shot
QPR came close to doubling their lead moments later when Barton's driven ball almost found an unmarked Helguson.
However, the tide began to turn soon afterwards and, after Olsson saw a free-kick hit the wall, Rovers levelled eight minutes after falling behind.
While struggling to dominate possession, Blackburn looked dangerous from set-pieces and equalised when Samba headed home Lowe's corner.
Level pegging: Blackburn celebrate Samba's strike
The Rovers skipper was back marshalling the defence shortly after as QPR went on the attack once more, with Shaun Wright-Phillips coming close with a fizzing 25-yard effort.
At the other end, an Olsson cross almost picked out Junior Hoilett, who then had a shot cleared off the line by Ferdinand after jinking past Shaun Derry and Barton.
Neither side managed to get a foothold on play in the opening 10 minutes of the second period, with the only moment of note a booking for Blackburn's Steven Nzonzi.
Benched: After his bus top antics, Adel Taarabt began the game as a substitute, coming on for Jamie Mackie after 64 minutes
Fitz Hall produced a superb block to thwart a run by the ever-impressive Olsson as the match began to liven up once again, with most of the play in the Rovers half.
Blackburn looked content to counter-attack and allowed QPR to boss possession, although they struggled to eke out any chances.
Wright-Phillips and Traore were booked as frustrations got the better of QPR, who replaced Mackie with talisman Adel Taarabt shortly afterwards.
Day in the sun: Neil Warnock (left) and Steve Kean observe proceedings
The Hoops looked lively after the Morocco international's introduction, although he was guilty of a heinous miss on his 100th league appearance for the club.
Wright-Phillips headed Taarabt through on goal but he somehow managed to skew a left-footed shot wide when the goal beckoned.
Taarabt mishit another shot in the 76th minute, before Lowe was booked for a nasty-looking challenge on Faurlin.
Bossing it: Alejando Faurlin (right) vies with Jason Lowe
QPR upped the ante in search of a late winner with the clock winding down.
Taarabt had a penalty shout turned down after a challenge by Salgado with six minutes remaining, which cameinbetween two poor headers from Hall.
QPR continued to press for a decidinggoal but it was Blackburn who almost grabbed victory in the dying seconds, with Paddy Kenny forced to save Olsson's shot in stoppage time.
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