Gary Gold admitted he had "very mixed emotions" after his Newcastle team were left facing Aviva Premiership relegation despite beating Wasps at Adams Park.
The Falcons finished bottom by a point following a 22-game regular league campaign that saw them win just six matches, including Saturday's 14-10 success against Wasps.
Newcastle's fate now rests on the outcome of this season's second-tier Championship title race, which will not be concluded until May 30.
Bristol, London Welsh, Bedford and Cornish Pirates are all contesting silverware, although it is thought only Bristol of that quartet categorically meet Premiership entry criteria.
Gold, who took interim charge of Newcastle in January and will now hand over the reins to Dean Richards, said: "It is a very emotional day, and the consequences are very upsetting.
"We were fighting for our lives. At 10-0 down there was perhaps a reason to give up, but the players didn't. They are a great bunch of guys who were up for the fight.
"My goal when I came to Newcastle was to keep them in the Premiership. I couldn't control the consequences today.
"The smart money will be on Richards inheriting a squad destined to play Championship rugby."
That will not, though, be an unfamiliar experience for the former England number eight, whose three-year worldwide coaching ban imposed following the infamous Bloodgate saga expires this summer.
Richards led Harlequins back into English rugby's top flight at the first time of asking in 2006, and Newcastle should encounter few problems making a rapid return.
But that prospect will not ease the pain for Gold and his players, who are now set to go their separate ways.
South African Gold is poised to succeed Sir Ian McGeechan at Bath, heading up a coaching team that could also include former England defence coach Mike Ford and ex-London Irish prop Neal Hatley.
Asked about his immediate future, Gold added: "I am going home [to South Africa] tomorrow, and I have some options to consider.
"We had to throw the kitchen sink at it today, but we had the belief we could do it.
"I wanted to hand the club over in a better state, and I think the players have improved significantly."
For their part, cash-strapped Wasps have secured Premiership status for next term, and they also hope that a takeover of the club will be completed by late May.
"I am confident the deal will be concluded," Wasps chairman Mark Rigby said after today's game.
"Terms have been agreed, solicitors have been instructed and we have entered a period of exclusivity.
"We are not prepared to identify the consortium because we are bound by a non-disclosure brief.
"While it is a hollow feeling to secure our Premiership status with a defeat, it means we will have top-flight rugby in Wycombe next season."
Despite wing Christian Wade scoring his ninth Premiership try of the season, Newcastle claimed their second successive league away win through second-half touchdowns by James Fitzpatrick and Peter Stringer.
Wasps rugby director David Young said: "It is a little bit of a funny feeling, but we have done our job in terms of staying in the Premiership.
"The season, especially since October, has been hugely difficult, and I don't want to go through another one like it. It has been very draining.
"But things are looking far more positive - the future is looking brighter."
