Jacob Murphy celebrated signing his professional contract by bagging a hat-trick to help Norwich Under-21s knock Lynn out of the Norfolk Senior Cup.

Murphy netted three times during a goal-crazy second half as City bagged five to see off a spirited Lynn who had been deservedly level at the break.

Danny Beaumont capped his first start since November 10 to put Lynn in front early on before Oli Durojaiye's 21st-minute penalty made it 1-1.

But it wasn't until the second half that the game really exploded when two goals in three minutes from Durojaiye and Murphy put a rampant City in control.

George Thomson's deflected strike gave Lynn hope of completing a comeback but Jamar Loza and Murphy netted to put the game out of the visitors' reach.

There was still time for Thomson to net a stunning half-volley to grab his second before Murphy went one better when he smashed home his third to seal the Canaries' youngsters place in the semi-finals.

The Carrow Road club's starlets went into the tie as favourites – especially having beating Lynn 1-0 away from home in last season's quarter-finals.

And with a host of hugely talented players destined to be Premier League, or at least Football League, stars of the future in their side, they were expected to beat Gary Setchell's non-league outfit.

The Lynn boss made a host of changes to his team that beat Stamford 2-1 on New Year's Day with regular starters Phil Gulliver, Richard Bunting and Russell Dunkley all left out of the squad.

Much like during their 3-0 win at Thetford Town in the last round, Setchell decided to shuffle his pack and give some much-needed game time to some of his so-called squad players.

Surprisingly, perhaps, it was a much-changed Lynn who started the game the better and took the lead in the fifth minute thanks to a mistake from City 'keeper Remi Matthews.

His poor attempt at finding a team-mate was cut out by Danny White, who played a one-two with Shane Tolley, before delivering an inch-perfect cross which Beaumont duly dispatched.

If the young Canaries can argue they didn't deserve to go behind, they couldn't claim they didn't spend the next spell camped in their own half as Lynn took control of proceedings.

Marshalled by a fired up captain Dan Quigley and creator-in-chief Thomson, who was revelling in a central-midfield role, Setchell's men were well on top – and enjoyed plenty of possession.

But Josh Murphy, playing on the left, showed a flash of his brilliance to create an opening for himself just after 15 minutes. Yet, his effort, despite being well hit, was straight at Lynn 'keeper Alex Street.

And soon it was Murphy again who showed why he, and his brother Jacob, are so highly-rated - and have just both been handed professional contracts by City - when they combined to help bring their side back into the game.

Josh played a raking cross-field ball to his brother, who had drifted in from the right flank, and he was brought down in the box by Jordan Yong.

Durojaiye coolly slotted the penalty home to make it 1-1 and his goal settled Scott Marshall's side down as they soon enjoyed their first spell of supremacy.

The game became something of a possession-fest as the opening 45 wore on with Loza and Jacob Murphy being the only players to see a slight opening in front of goal.

The latter fizzed a long-range effort wide while the former was only denied by a superb block from ex-City Academy star Ryan Fryatt – now shining, once again, in Lynn colours.

The even encounter was turned on its head by the young Canaries' flying start to the second half as Durojaiye and Jacob Murphy netted in quick succession.

Sloppy marking from a corner allowed Josh Murphy to have an unchallenged shot at goal. And while Street did well to save it, Durojaiye slotted home the rebound from close range to bag his second.

Before Lynn had a chance to recover, right-sided winger Jacob Murphy extended his outfit's lead with a stunning 25-yarder which Street did well to even get fingertips on.

The Canaries' flying start to the second period continued as they threatened to blow Setchell's men away.

Street made a fine save from a Jacob Murphy cross before Fryatt made a crucial deflection to turn Cameron King's goal-bound effort just over the bar.

The next opportunity for Marshall's rampant men was a golden one which King spurned. Three yards out, and with the goal gaping at him, the City striker somehow hooked horribly over.

At the other end, Lynn's regular goal machine Steve Spriggs – who came on for Tolley before the break – missed a great chance himself.

But a heavily deflected Thomson effort from long range reduced the deficit to make it 3-2 – and at the same time helped stem the flow of constant City pressure.

The goal swung the game hugely back in the Linnets favour as Quigley and Jamie Thurlbourne went close. Lynn were pressing hard for an equaliser.

But, again, two goals in three minutes turned the game on its head when Loza slotted home from inches out after Reece Hall-Johnson's effort was deflected into his path.

Jacob Murphy soon put the game beyond Lynn when his left-footed shot arrowed into the bottom corner.

Still, Thomson reduced the deficit as a breathless second-half of end-to-end football continued. The midfielder's stunning half-volley from at least 30 yards ensured he capped a fine individual display by netting twice.

But not to be outdone, one of City's brightest hopes for the future – Jacob Murphy – completed his treble with a fine run and finish to seal Norwich's place in the last four.

Norwich: Matthews, McNeil, Toffolo, Clunan (McGeehan, 85), McFadden (Norman, 78), Gafaiti, Jacob Murphy, Oli Durojaiye, Loza, King (Hall-Johnson, 78), Josh Murphy. Subs not used: Wyatt, Morris. Booked: Durojaiye. Goals: Durojaiye (pen, 21, 48), Jacob Murphy (50, 83, 89), Loza (80)

Lynn: Street, Buhlemann, Fryatt (Biles, 81), Lee, Yong (Watson, 54), White, Thomson, Quigley, Thurlbourne, Tolley (Spriggs, 41), Beaumont. Subs not used: Gay, McLeish. Booked: Fryatt. Goals: Beaumont (5), Thomson (60, 87)

Referee: S. Meale

Attendance: 207

- Pictures will be added to this report soon.