An error by Arsenal goalkeeper Jens Lehmann gave battling Blackburn a draw at Ewood Park.
Jubilant Dunn celebrates scoring the Blackburn equaliser
He let David Dunn's 25-yard strike slip through his fingers in the 72nd minute as the Gunners seemed set for victory.
Earlier, another keeping error from Brad Friedel on 18 minutes led to Robin Van Persie putting Arsenal ahead.
But Blackburn deserved their point after playing the last 10 minutes with 10 men after Ryan Nelsen was sent off - in a match with seven other bookings.
Blackburn, defending a seven-match unbeaten Premier League run dating back to last season, started brightly, with former Arsenal striker David Bentley looking dangerous.
But it was 18-year-old Theo Walcott, recalled to the Arsenal side for the injured Tomas Rosicky, who created the first real chance.
The England striker burst upfield and threaded an incisive ball through to debut man Eduardo Da Silva, although Friedel was quickly out of his penalty area to clear to safety.
Arsenal had a scare after six minutes when Brett Emerton's teasing cross from the right was punched clear by Lehmann, only for the German keeper to clatter into the back of his own defender Kolo Toure.
Lehmann looked groggy for a while but managed to clear his head to carry on.
And the Arsenal breakthrough finally came when Aleksandr Hleb and Cesc Fabregas combined well to set up Gael Clichy to cross from the left.
The ball was nodded back by Walcott at the far post, giving Da Silva a chance, but Friedel , on his 250th Premier League appearance, allowed the ball to spill away, giving Van Persie the easiest of chances to fire home from close range.
Arsenal suffered a setback moments later when skipper William Gallas was forced off after twisting his knee when making a tackle. He gestured towards the Gunners bench the moment he hit the deck and was replaced by Philippe Senderos, with Toure taking the captaincy.
And Toure immediately rose to the occasion with a fantastic tackle to block Matt Derbyshire's attempt when he was presented with a free strike on goal after a good ball from Bentley.
Then Bentley was booked for bringing down Van Persie in a move that wrestler Big Daddy would have been proud of - and that sparked a flurry of further yellow cards as the game became increasingly competitive.
Arsenal should have added another goal when Walcott broke clear again down the right but he flashed the ball across the Rovers penalty area when he would have done better by shooting at the target himself.
Van Persie celebrates Arsenal's opener at Ewood Park
Stephen Warnock then made a super-human interception to deny Mathieu Flamini pulling the trigger when put through by Hleb in the dying minutes of the first half.
Blackburn appealed for a penalty just after the restart when Robbie Savage seemed to be brought down by Toure as the Rovers midfielder burst into the penalty box but referee Alan Wiley waved play on.
Rovers were pushing for the leveller and went close when Roque Santa Cruz's flick from Bentley's free-kick drifted wide of the far post.
Then Samba made a penalty claim as Fabregas stopped his goal-bound effort with what looked like an outstretched arm in the home side's best spell of the match.
But Blackburn's moment of joy came in the 71st minute when Dunn's crisp drive slipped through Lehmann's normally rock-solid hands.
It was the first goal for the midfielder since he returned to Blackburn in January after a four-year spell at Birmingham.
Rovers sensed blood and pushed for the winner, although there was still time for referee Wiley to send off Nelsen - the eighth Blackburn player he has sent off in six years.
Blackburn: Friedel, Emerton, Samba, Nelsen, Warnock, Bentley, Savage, Dunn, Pedersen, Santa Cruz (McCarthy 88), Derbyshire (Ooijer 85). Subs Not Used: Brown, Kerimoglu, Roberts.
Sent Off: Nelsen (84).
Booked: Bentley, Samba, Savage, Nelsen.
Goal: Dunn 72.
Arsenal: Lehmann, Sagna, Toure, Gallas (Senderos 24), Clichy, Walcott (Bendtner 73), Flamini, Fabregas, Hleb, Eduardo (Denilson 65), Van Persie. Subs Not Used: Almunia, Song Billong.
Booked: Flamini, Eduardo, Clichy, Van Persie.
Goal: Van Persie 18.
Ref: Alan Wiley (Staffordshire).