London Irish will meet Gloucester in the final of the European Challenge Cup after a dramatic win at Newcastle.
Newcastle (3) 22
Tries: Woods, May, Tait
Cons: Wilkinson 2
London Irish: (15) 27
Tries: Russell, Ojo, Tagicakibau, Tiesi
Cons: Flutey 2
Tries from Robbie Russell and Topsy Ojo gave the Exiles a 15-3 half-time lead.
The visitors ran in further tries from Sailosi Tagicakibau and Gonzalo Tiesi, with Riki Flutey kicking seven points, to leave Newcastle trailing 27-3.
Ben Woods, Tom May and Mathew Tait then scored late tries for the Falcons, with Jonny Wilkinson adding two conversions, but London Irish just held on.
Matthew Burke's penalty gave Newcastle an early lead but the visitors took the lead after 16 minutes when Russell finished off a sustained attack.
Flutey converted and added a penalty five minutes later and when Ojo exploited some poor tackling to cross for their second try - this time unconverted - the Exiles led 15-3 after 30 minutes.
Newcastle boss Rob Andrew responded by bringing on Wilkinson, making his second appearance after the latest in his series of injuries.
He did his best to spark the Falcons but tries from Sailosi Tagicakibau, converted by Flutey, and Gonzalo Tiesei put the Exiles well clear.
Newcastle then finally came to life, with Woods, May and Tait going over for late tries, but their inability to win their own throws at line-outs ultimately cost the Falcons dear.
Newcastle director of rugby Rob Andrew:
"It would have been some comeback from 27-3 down to win 29-27, which to be honest I thought we were going to do.
"There is some debate about whether we scored from that lineout at the end and even when we didn't, I was confident we would score from the scrum - but we didn't and we probably chose the wrong option there."
London Irish head coach Brian Smith:
"We were very happy with our defensive line-out performance when were really on the rack in the last 20 minutes.
"We turned it over as couple of times, which was very important, because we had no possession in that final 20 minutes - it's to Newcastle's credit that they ran us so close."
Newcastle: Burke; May, Tait, Noon, Elliot; Walder, Grindal; Ward, Long, Morris; Perry, Parling; McCarthy, Woods, Charvis (capt).
Replacements: Williams, Thompson, Finegan, Harris, Flood, Charlton, Wilkinson.
London Irish: Armitage; Ojo, Tiesi, Catt (capt), Tagicakibau; Flutey, Hodgson; Hatley, Russell, Rautenbach; Casey, Roche; Danaher, Magne, Murphy.
Replacements: Collins, Paice, Skuse, Kennedy, Leguizamon, Edwards, Geraghty.
Referee: Nigel Owens (Wales).