Portsmouth refused to allow Arsenal to climb back to the summit of the Premier League by holding them to a deserved 0-0 draw at Fratton Park.
The Gunners, who had not been beaten by Pompey since 1958, now find themselves playing catch-up with Manchester United, who are a point clear following their demolition of Sunderland.
Arsene Wenger's side spurned late chances to take the three points they required to go back top but were disappointing overall and a Pompey back line marshalled ably by ex-Gunner Sol Campbell refused to be breached.
• Campbell hails defensive effortIt was the fifth game in a row that Harry Redknapp's side had failed to give the fans a goal at home but the result could prove significant as the race for the title enters a significant phase.
Arsenal began strongly with Emmanuel Eboue causing trouble down the right flank. His first-minute cross just eluded the head of Cesc Fabregas right in front of goal but a one-two with Emmanuel Adebayor saw the Frenchman fire wildly over.
His next effort, from the edge of the box, was much better but home goalkeeper David James was able to get behind his low drive.
Pompey were guilty of playing too many nervous long balls in the opening exchanges but they soon calmed down once the recalled Kanu and top scorer Benjani began to link up regularly.
Benjani, who was required to operate as a right-sided midfielder when Arsenal were in possession, won a free-kick on the right when Gael Clichy was adjudged to have used an arm in the 18th minute.
The resulting free-kick, although initially botched by Sulley Muntari, led to the best chance of the first half. Muntari's second attempt at delivering the ball into a crowded box was brought down by Papa Bouba Diop, who lost no time in firing in a powerful drive that Manuel Almunia did well to divert round his right-hand post.
The Spaniard will soon qualify for England through residency rules and the away fans rewarded him with a chant of ``England's Number One''.
James still covets that accolade despite his advancing years and a period under Steve McClaren when he was ignored for international duties.
But the veteran showed he was still capable of a good-looking save when he threw himself skywards to stop Tomas Rosicky's curled effort from reaching the top corner in the 37th minute.
Niko Kranjcar had already fired an effort just wide at the other end having neatly turned Bacary Sagna to tee up his favoured left foot but the Croatian was involved in an incident just before the break that left Arsenal skipper William Gallas hurt. First Kanu and then Kranjcar challenged the Frenchman, who hobbled off with an ankle problem.
Gallas was able to continue wearing the armband for the second half and there was a nervous moment for the home fans when Hermann Hreidarsson made a full-blooded challenge on Kolo Toure in the Portsmouth area.
There was no margin for error but although the Arsenal man went down, the Iceland international had made enough contact with the ball for the liking of referee Steve Bennett, who then booked Lauren - another of Pompey's ex-Arsenal men - for tugging Rosicky back by the shirt.
Eboue was next in the book for a foul on Diop and, after Kanu had fired wildly off target on the turn, Arsenal swapped Eboue for Abou Diaby with 25 minutes still on the clock.
Almunia was required to get behind efforts from Benjani and then Kranjcar as the home side continued to believe the evening could yet be settled in their favour.
Indeed, Benjani, with eight goals to his name already this season, almost made it happen in the 75th minute when Kanu's superb through-ball put him clear of the Arsenal back line.
Almunia came out to meet him and succeeded in slowing down his path forwards as the man from Zimbabwe had to veer off at an angle.
And that was enough for Clichy, who used his prodigious pace to intercept and the chance evaporated as soon as it was clear that referee Bennett regarded the challenge as legal.
Benjani was replaced by John Utaka after Diop had been booked for a foul on Alex Hleb, who was swapped for Nicklas Bendtner, the goal hero of Saturday's 2-1 derby win over Spurs.
Gallas has also been a source of late goals and might have won it for the Gunners with three minutes remaining after he controlled a Fabregas shot and fired goalwards on the turn from six yards.
The ball flew just over and Portsmouth were fortunate referee Bennett did not penalise Campbell for has late challenge on the Frenchman.
Four minutes of added time followed but the game was destined to remain scoreless when Rosicky scuffed a great final chance wide.
# Campbell hails defensive effort
Sol Campbell savoured Portsmouth's hard-earned clean sheet against free-scoring Arsenal at Fratton Park tonight.
Arsenal needed a win to climb back above Manchester United to the top of the Premier League but could not find a way past a Pompey defence well marshalled by former Gunner Campbell.
'We had to battle hard because Arsenal are a great side,' England defender Campbell told Sky Sports 1.
'They had a couple of chances at the end but it was a great shift by the lads,' said Campbell.
'We wanted to get in their faces, put them under pressure and not let them settle on the ball. If you let them pass they will pass you to death.'
'We had a couple of chances of our own but it was not to be. Benjani had a chance but their `keeper came out quickly. It was a shame but that is the way it goes sometimes.'
Arsenal boss Arsene Wenger admitted his side had been frustrated by Portsmouth's defensive approach but had no complaints.
Wenger told Sky Sports: 'They defended very well, they were organised not to concede.
'It was a very good defensive performance, their minds were completely on defending. We were not at our best today but gave absolutely everything.
'Credit to Portsmouth, they made it difficult for us. They played in one half of the pitch. I don't think offensively they had a special performance, they played with 10 players at the back and in the end they got the maximum they could from this kind of game.'
Wenger was disappointed to have lost top spot but was not overly concerned.
He added: 'We would prefer to be at the top but it is very tight - only one point.'
Portsmouth boss Harry Redknapp was delighted that his side had managed to blunt the Gunners and claim a point.
'A clean sheet against Arsenal is excellent. We worked our socks off. We worked hard and closed them down,' he said.
'We played the same system - one up front and others looking to join in - and I thought we had the best chance of the match when `Benji' went through.'
Redknapp bristled when told that Wenger had been surprised by Pompey's approach to the match and their reliance on solid defending.
'When you haven't got the ball you have to defend,' replied Redknapp. 'There is not a team in the country that is harder to get the ball off than Arsenal. You have to be disciplined and maintain your positions or you get ripped to pieces. Were we supposed to lie down and get ripped to pieces?'
Asked if Pompey's point had cheered him up after the defeats against Tottenham and Liverpool, Redknapp replied tongue-in-cheek: 'Yes, we've been on a real bad run at Portsmouth........11 games unbeaten (before the Spurs match). It was a great point for us today. Thoroughly deserved.'
