Arsenal injected new life into their title bid as Abou Diaby's header saw them end a three-game winless sequence with victory over Liverpool.Both teams struggled for momentum in a dour first half but the game came alive after the interval as David Ngog and Tomas Rosicky went close.Rosicky blasted over and Diaby then capped a period of Arsenal pressure by powering in from the Czech's cross.Ryan Babel's drive was tipped on to the bar but Liverpool could not level.Although Rafael Benitez's men pushed hard to salvage a point, subjecting the Gunners to attack after attack late on, Arsenal held out for what could prove a critical win.With leaders Chelsea losing at Everton and Manchester United drawing at Aston Villa, Arsene Wenger's side move to within six points of leaders Chelsea and five of Manchester United.They do not play 'big four' opposition again this season and will feel their campaign is back on track after successive defeats by United and Chelsea.Serious questions have been asked about Arsenal's credentials to win a first Premier League crown since 2004 but, on this evidence, there is life in them yet.Liverpool remain fourth in the table but slip eight points behind the Gunners after their first defeat in eight games.The Reds are still yet to win at the Emirates Stadium but could not have worked harder to come away with something, especially as they flooded forward at the death.Liverpool captain Steven Gerrard talked of the need to afford Arsenal as little space as possible and the tactic worked for long periods.But the hosts were equal to the challenge and, in turn, prevented the visitors from establishing any sort of rhythm until the final quarter.Benitez made one alteration to his back four as Martin Skrtel replaced the suspended Sotirios Krygiakos, yet it was still easy to see why Liverpool arrived unbeaten in seven league games with four successive clean sheets.In the first half they were rarely troubled by Arsenal forwards Nicklas Bendtner or Andrey Arshavin, although Bendtner did slice over from an acute angle after being played in by his strike partner.Liverpool felt they should have had a penalty when Maxi Rodriguez's strike appeared to cannon into the arm of Thomas Vermaelen and Pepe Reina saved comfortably from Cesc Fabregas.The half-time whistle came as a relief and, fortunately for all concerned, the second period was a more open affair from the first whistle.Arshavin drilled a venomous effort into the side-netting and Lucas shot just over when put through by Dirk Kuyt after some careless defending by Gael Clichy.Both teams were pressing hard for an opener and suddenly the standard of play began to soar.Gerrard took control of a counter-attack to send Ngog scurrying away but William Gallas slid in with a perfectly-timed tackle as his fellow Frenchman was about to shoot.At the other end, Arshavin put Rosicky away but he lacked composure and miscontrolled before Bendtner saw an effort scrambled clear.By now there was a pulsating ebb and flow to the game and the hosts were beginning to dictate, Rosicky flashing inches over via a Javier Mascherano deflection.It felt like the deadlock would soon be broken and so it proved.Bendtner showed fine persistence to feed Rosicky on the right and he curled in a superb cross for the unmarked Diaby to head home.Liverpool came straight back at their opponents and Arsenal goalkeeper Manuel Almunia brilliantly tipped Babel's fizzing strike on to the bar.Benitez's team earned a number of free-kicks in dangerous areas but failed to capitalise.One set-piece from Gerrard appeared to hit the arm of Fabregas in the wall but referee Howard Webb waved away their appeals, leaving Wenger to celebrate his 300th Premier League win.Liverpool manager Rafael Benitez: "It was a pity because in the last 20 minutes we were pushing hard and had chances."It was just quality in final third that made the big difference. The second half was much better and we could have got something."It's important for us to have a good run of results. There's a long way to go and we need to keep on going."Source: BBC