Harlequins went top of the Premiership after beating Newcastle 40-12.

Alex Dombrandt got on the end of a lovely move to seal the bonus point for Quins early in the second period.

Louis Lynagh got a fifth try, while Newcastle replied with a penalty try before Tyrone Green scored in style.

Marcus Smith - on as a Quins replacement after returning from World Cup duty with England - floated a kick towards the right corner and Green acrobatically dived to gather and dot down for what will be a contender for try of the season.

Jamie Blamire broke through in the final minute for a second Falcons try to get Newcastle into double figures.

Matias Moroni should have put Newcastle ahead in the fifth minute as he dived for the corner, but Lennox Anyanwu did superbly to get between the ball and the ground as the Argentine was forced into touch.

Byrne's yellow card proved to be significant as seconds later Riley drove over from a close-range lineout and Lamb got on the end of a wonderful six-pass move from right to left to get the hosts' second try.

Falcons twice got turned over deep in Harlequins territory in the final 10 minutes of the half, and they were made to pay when David - celebrating his 25th birthday - went over after a lovely offload from Dombrandt.

Dombrandt, who was overlooked for England's World Cup squad, got the fourth try nine minutes into the second period after superb offloads from Riley and Fin Baxter, and four minutes later the Quins skipper put Lynagh in for a try on his 50th appearance.

Lamb was yellow-carded after cynically going off his feet to stop Newcastle when they were in close range, and after heavy pressure the visitors got themselves a 65th-minute penalty try as a maul from a scrum was brought down.

Green's late effort provided what should be the enduring memory of the match as the South African got his first try of the season, before Blamire broke through to get a consolation try after a lineout.

Harlequins director of rugby Billy Millard:

"Tyrone has been out for a long time and that connection between him and Marcus is pretty special.

"Obviously they haven't played for a while but Tyrone is getting better and better each week. From minute one, Marcus is bouncing and talking and all over them, so it's awesome to have him back.

"Alex is just surging at the minute, his timing, his confidence and his ball carrying, he's gone up a gear in his leadership and he's been immense for us."

"I'm always pleased with a bonus point win at home and we've got too massive ones in front of us so it was important to keep momentum.

Newcastle head coach Alex Codling:

"I thought in the first half we dominated for large parts but it's a microcosm of our season.

"We didn't get over the line, held up, knocked on. Quins are extremely clinical. They took the chances and we didn't, that's the bottom line.

"It's the theme of the first four games. The margins in this league are too small if you make mistakes and we made too many, most of our own doing and we came up short.

"We're just like a boxer at the minute, we throw loads of jabs but just can't find the knockout punch. We've got Saracens next week so we better find it quick.

Harlequins: David; Green, Beard, Anyanwu, Lynagh; J Evans, Porter; Baxter, Riley, Collier, Launchbury, Hammond, Lamb, W Evans, Dombrandt (capt)

Replacements: Jibulu, Marler, Lewis, Cunningham-South, Chisholm, Green, Smith, Bradley

Sin-bin: Lamb (65)

Newcastle: Obatoyinbo; Radwan, Moroni, Orlando, Carreras; Jennings, O'Sullivan; Brocklebank, Byrne, Tampin, Rubiolo, McDonald, Cross, Pepper, Chick (capt).

Replacements: Blamire, Brantingham, Bello, Hawkins, Bainbridge, Stuart, Connon, Wacokecoke.

Sin-bin: Byrne (15)

Referee: Jack Makepeace