Harlequins (31) 31
Easter 2, Fuga, Brown, Monye Cons:
Newcastle (7) 12
Parling, Charlton Cons:
Mike Brown's try secured the bonus-point win
An awesome first-half display saw Harlequins book a home Premiership semi-final place against London Irish.
Quins secured their bonus point within the half hour courtesy of two tries from Nick Easter and a touchdown each for Tani Fuga and Mike Brown.
The Falcons hit back with a score from Andy Parling, but Quins bagged a fifth try before half-time through Ugo Monye.
Quins failed to add to their tally after the interval, but Hall Charlton claimed a late try for the visitors.
With the knowledge that a bonus-point victory would guarantee second place in the Premiership behind Leicester, Quins began aggressively and were rewarded for their attacking intent inside seven minutes.
A quick Danny Care tap penalty allowed Easter, with plenty of support from his fellow forwards, to barge over the Falcons tryline, a score converted by Waisea Luveniyali.
The England number eight added his second 10 minutes later when he latched on to Jordan Turner-Hall's pass and used his upper body strength to take him over the whitewash, despite the attentions of several defenders.
Brown sent hooker Fuga over near the left corner flag on 21 minutes before the full-back added the fourth, courtesy of fine handling skills from Care, who enhanced his prospects for a Lions replacement call following a season-ending injury to Ireland scrum-half Tomas O'Leary.
Newcastle eventually responded with a try from their first threatening sortie into Quins territory as Parling, a 22nd-minute replacement for injured number eight Adam Balding, barged over for five points.
Monye demonstrated the form which earned him a Lions spot with a superb individual score, selling a dummy to full-back Alex Tait before using his considerable place to dive over in the corner two minutes before the interval.
The Falcons managed to get into double figures when second-half replacement scrum-half Charlton grabbed a late touchdown.
But the afternoon belonged to Quins, who will be confident of home success against the Exiles after yet another fine display.
Harlequins boss Dean Richards on Danny Care's prospects of replacing Tomas O'Leary in the Lions squad:
"I think they'll look at him but whether they'll take Danny or Dwayne Peel, you never know. It depends whether they go for experience or technical ability or just flair.
"Ian McGeechan (Lions coach) was here two weeks ago and mentioned he had come to watch Danny play, along with some other guys, so he is obviously in their minds but it will come down to whether they feel he is the right person to fit into their plans.
"The first 30 minutes was something special. We were outstanding and were well worth our four tries."
Newcastle director of rugby Steve Bates
"Last week (at home to Bath) was a massive game when we said goodbye to a lot of players and this was one of those games that was one step too far but I was really proud of the way the boys came back in the second half.
"Fair play to them, they were very good in the first half, very robust, moved the ball well and played quickly.
"It's probably why they are in the top four and we've got to learn some lessons from that."
Brown; Williams, Tiesi, Turner-Hall, Monye; Luveniyali, Care; Jones, Fuga, Ross; Percival, Robson; Robshaw, Skinner (capt), Easter.
Brooker, Lambert, Evans, Guest, Gomarsall, Barry, Stegmann.
A Tait; D Williams, Noon, Tu'ipulotu, Rudd; May, Young; Ward, Thompson, Wilson, Swinson, Sorenson, Winter, Dowson (capt), Balding.
Long, J Williams, Parling, Beattie, Charlton, Jones, Miller.