|Newcastle (10) 13|
|Try: Watson Con: Delany Pens: Delany, Socino|
|London Irish (6) 6|
|Pens: Tonks 2|
Newcastle Falcons produced a superb second-half defensive display to beat London Irish and pull seven points clear of the Premiership's bottom club.
The Exiles, members of the top flight since 1996, face Harlequins and Wasps in their two remaining fixtures.
Greig Tonks had kicked them in front at Kingston Park, but Marcus Watson's try and penalties from Mike Delany and Juan Pablo Socino put Falcons 13-6 ahead.
London Irish dominated after half-time but were unable to break through.
They now need to earn surprise victories over Quins and high-flying Wasps if they are to have any chance of catching 11th-placed Newcastle, who play Saracens and Sale in the last two rounds.
Tom Coventry's Irish side created numerous try-scoring opportunities, only to be thwarted by a combination of resolute Falcons defence, wayward handling and poor decision-making at the crucial moment.
Asaeli Tikoirotuma was arguably most guilty, attempting an ambitious offload when presented with a straightforward 10-metre finish to the corner, while Andrew Fenby was unlucky not to successfully ground Shane Geraghty's grubber through.
Even Newcastle's first-half try came from a London Irish error, as Tonks' pass on the edge of the Newcastle 22 was intercepted by Watson for an eye-catching 60-metre touchdown.
Newcastle director of rugby Dean Richards:
"The job is not done yet. We talked about it after the final whistle and there will be no letting up in the last two games of the season.
"We were the best of two bad sides. It was disappointing to score only one try, but we didn't let them score any and our defence and discipline, especially in the last 25 minutes, was outstanding.
"If you play badly and win, you have to take it. London Irish are not an easy side to crack. They have been playing well in recent weeks.
"Mathematically, safety is not there. We just have to make sure it is in the last two games."
London Irish head coach Tom Coventry told BBC Radio Berkshire:
"We had plenty of chances, we just weren't able to execute them under pressure. It's probably a sign of a team lacking in confidence.
"The ability to time a pass, the injection to take a couple of extra steps before you offload and confidence in your ability to do that.
"We're at the bottom of a crest at the moment and those things don't come naturally to you."
On the seven-point deficit at the bottom with two games to play: "There's always hope, it's not a hopeless situation.
"We've just got to keep ourselves in a good state of mind. We certainly don't look for excuses."
Newcastle: Hammersley; Tait, Tiesi, Socino, Watson; Delany, Young; Vickers, McGuigan, Vea, Green, Robinson, Wilson, Welch (capt), Latu.
Replacements: Lawson, Rogers, Cusack, Botha, Hogg, Takulua, Willis, Harris.
London Irish: Maitland; Lewington, Hearn, Williams, Fenby; Tonks, Steele; Court, Paice, Aulika, Lloyd, Symons, Sinclair, Cowan, Narraway (capt).
Replacements: Cruse, Smallbone, Halavatau, Sexton, McCusker, McKibbin, Geraghty, Tikoirotuma.
Referee: Wayne Barnes (RFU).
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