Gareth Bale and Aaron Lennon's goals helped Tottenham Hotspur strike a decisive blow in the race for Champions League qualification after defeating north London rivals Arsenal at White Hart Lane.
Spurs now lead The Gunners by seven-points with 10 games remaining after Bale and Lennon both exposed the visitors' high defensive line within three first half minutes.
Per Mertesacker's flicked header deflected off Bale to halve the deficit five minutes after the break, but Tottenham held out to continue their hopes of reaching the Champions League and finishing above their city rivals for the first time since 1995 after 12th league game unbeaten moved them up to third.
Arsenal remain five points behind fourth place Chelsea and require heroics akin to last season, where they trailed fourth spot by 10 points, if they are to reach Europe's premier club competition for a 16th consecutive campaign.
The latest north London derby encounter between the two sides was to prove potentially pivotal in the race for Champions League qualification, with Arsenal four points adrift of Tottenham at kick-off.
Gylfi Sigurdson was preferred to Lewis Holtby while Aaron Ramsey began in midfield for the visitors as Lukas Podolski was omitted.
With both sides adopting a high line, the visitors enjoyed the better of the opening exchanges, Olivier Giroud testing Hugo Lloris from Jack Wilshere's corner before Kyle Walker cut out a through ball towards Theo Walcott.
But as Spurs had shown in dispatches this season, in Bale they possess player capable of turning even the tightest of contests and the Welshman provided the crucial break-through eight minutes before the break.
Sigurdson exposed the space in behind to find Bale, who flicked the ball beyond Wojciech Szczesny to net his 16th league goal of the season.
And two minutes later Tottenham produced an identical move to double their lead as Scott Parker played in Lennon, who took advantage of a hesitant Nacho Monreal and Thomas Vermaelen to round Szczesny and tap home.
The Gunners were in desperate need of some inspiration with their European dream looking all the more distant, and they indeed grabbed a life-line when Mertesacker's header went in off Bale.
Bale almost made amends, but side-footed over the bar from seven yards out, and when Sigurdson passed up the opportunity to reestablish Spurs' two goal lead when opting to pass when put clear but substitute Jermain Defoe, Andre Villas-Boas would have been forgiven for fearing the worst.
Despite the introduction of Tomas Rosicky and Podolski Arsenal produced scant throughout the remainder, with Ramsey spurning the best opportunity as he fired wide as Spurs held out to tighten their grip on a top four place and pile the pressure on Arsene Wenger.