Harlequins made it 13 wins from 13 this season and extended their Premiership lead to nine points in a bruising battle with Newcastle.
Quins wing Seb Stegmann and Danny Care went over in the first half with Jeremy Manning responding for the visitors.
Newcastle had Tim Swinson and Chris Pilgrim sin-binned when Luke Wallace added Quins' third from a driving maul.
Mike Brown's try added the bonus point before Stegmann scored his second and James Johnston crossed at the death.
The result, combined with Worcester's win over Bath on Friday, leaves Newcastle nine points adrift at the foot of the table.
They contained their hosts well for the opening 15 minutes before Evans slotted his first shot at goal with ease.
The visitors fashioned slender chances in the opening stages but all the possession and territory belonged to Harlequins.
The Falcons looked to have the danger covered on the half hour but Newcastle full-back Jeremy Manning fell off his tackle and winger Stegmann went over.
Evans added the two points but Manning made up for his error with a try five minutes before half-time after Jimmy Gopperth switched play and caught out the home defence.
Manning's momentum carried him over the line but Gopperth could not add the conversion.
With half-time approaching Quins turned over possession from a promising Newcastle attack and ran out of their 22 to allow Care over in the corner.
Evans missed the extras and, after Will Skinner replaced Nick Easter, the sides turned around with the hosts 15-5 ahead.
Gopperth was again wide of the mark with a shot at goal shortly after the break and Falcons were soon on the back foot again, but defended vigorously.
Swinson was sin-binned for knocking the ball out of Care's hands but his team's resolve held out under extreme pressure.
Easter's presence was missed as Quins repeatedly butchered scoring opportunities by losing control of the ball at the base of the scrum.
The visitors went down to 13 when Pilgrim was yellow-carded for a high tackle.
A driving maul from a line-out saw Wallace eventually score and soon after, with Falcons still a man down, Brown went over out wide for a fully-deserved try that ensured the five points.
Newcastle pushed on but again they were caught out by Quins' counter-attack, as Brown and Care combined to put Stegmann in for his second.
Harlequins directior of rugby Conor O'Shea:
"That was incredibly physical. We have some walking wounded in the dressing room, but they'll get over it.
"The win is fantastic because Nick Easter spoke to the players before the game and said they'd really have to turn up or get beaten. They turned up.
"He played fantastically well in the first half before tweaking an ankle which is why he went off.
"Jordan Turner-Hall is pretty beaten up after making the mistake of running into Taiasina Tu'ifua, and there's only ever one winner in that situation."
Newcastle head coach Alan Tait:
"We have some guys a bit busted up in there, but they are the top side in the division and we pushed them at times only to let ourselves down with poor finishing.
"We say it every week in the dressing room but then we go out and give sloppy offloads, throwing the ball away. One minute we are attacking, the next they are away off our ball and scoring tries.
"I'll make some of them watch the video of the game during the week because we cannot keep doing this."
Harlequins: Brown; Stegmann, Hooper, Turner-Hall, S Smith; Evans, Care; Marler, Brooker, Johnston; Vallejos, Robson; Fa'asavalu, Wallace, Easter.
Replacements: Casson for Turner-Hall (68), Clegg for Evans (66), Mayhew for Marler (66), Gray for Brooker (56), Matthews for Fa'asavalu (74), Skinner for Easter (39).
Newcastle: Manning; Tait, Helleur, Fitzpatrick, Hufanga; Gopperth, Pilgrim; Wells, M Mayhew, Hall; Hudson (capt), van der Heijden; Swinson, Hogg, Tu'ifua.
Replacements: Goosen for Manning (68), Sheriffe for Tait (41), Pasqualin for Pilgrim (66), Shiells for Wells (53), Graham for M. Mayhew (66), Frazier for Hall (66), Fondse for Swinson (66), Welch for Tu'ifua (60).
Sin Bin: Swinson (48), Pilgrim (54).
Ref: Luke Pearce (RFU).