The in-form striker netted from the penalty spot, tapped home from close range and drilled into the corner after 15, 35 and 72 minutes to make it 17 goals in 16 outings in arguably our reserves' finest hour this season.
But it wasn't all about 'Barney'. Up against an young Arsenal side that nevertheless had six players who featured in Carling Cup action this season, Michael Malcolm capped another fine display with the fourth goal, Mark Yeates was at his impish best down the left and Johnnie Jackson ran the show from central midfield. Robert Burch also made an impressive return from injury in goal.
As expected, it was lively from the off and we fashioned the first chance in the first minute, Malcolm's flick released Limbersky and the Czech winger did well to hold off a couple of challenges before crossing low to O'Hara, who fired over.
Unfortunately, a rare error from Mills handed Arsenal the lead after eight minutes. Dilevski looked to pass back to Burch, Mills was in the way and slipped on the ball and left Smith through on goal. Burch did well to block his effort but Lupoli rolled in the rebound.
It took eight minutes to level. Yeates probed away down the left channel and was tripped in the box by O'Donnell and after lengthy protests and a booking, Barnard sent Taylor the wrong way for his 15th goal in 16 games.
Taylor did well to cling onto Yeates' low free-kick after 20 minutes as Barnard and Malcolm waited to pounce and Jackson was in the right place to block as Lupoli pulled the trigger from the edge of the box after 27 minutes.
The likes of Barnard, Malcolm, Jackson and O'Hara refused to let Arsenal settle on the ball and that led directly to the second goal. O'Hara's tackle dispossessed Djourou 30 yards out, Jackson took over and lashed a shot from 20 yards that Taylor could only parry and Barnard was there to tap home the rebound, 2-1, 35 minutes.
Arsenal were rattled but had a chance to level out of nothing a few minutes later when Lupoli latched onto Skulasson's hack upfield only to fail miserably in his attempt to lob Burch.
There was a scare at the start of the second half as Burch came sliding out to meet Larssson, gathered the ball cleanly only for his momentum to take him out of the area. Hearts were in mouths as we waited for the colour of the card but thankfully it was yellow. O'Donnell's free-kick flashed across goal, inches away from Skulasson.
We hit back straight away with Malcolm poking Jackson's free-kick just wide from eight yards.
We took over for the next 10 minutes, carving out a host of chances. Barnard linked well with Malcolm before curling wide, Yeates shot straight at Taylor after working a yard in the box and Mills couldn't keep his close-range header down from Yeates' corner. Jackson came closest of the lot on the hour when he picked up a loose ball in midfield, travelled 20 yards and hit a low drive that Taylor tipped onto the post.
A goal had to come and it arrived with 63 minutes on the clock. Yeates whipped in a free-kick from the left touchline and Malcolm was there to convert from close range at the far post.
Gilbert missed the chance to pull a goal back when he struck Owusu-Abeyie's miscued shot into the side-netting after 68 minutes and Burch was out smartly to block with his legs after Gregg sent substitute Birchall through one-on-one.
Just as the Gunners looked dangerous though, Barnard pounced for his hat-trick after 72 minutes. The goal owed a lot to Jackson's quick thinking as, with Arsenal asleep, he dinked a quick free-kick over the top for Barnard. The striker controlled and drilled his shot across Taylor into the far corner.
Arsenal responded four minutes later. Smith's cross went through a couple of bodies and struck the unsuspecting Hallfredsson on the hand, the penalty was awarded and Smith sent Burch the wrong way for 4-2.
Lupoli's excellent solo goal in injury time - a run and shot into the top corner - was thankfully no more than a consolation.
8mins: GOAL. Bit of a catastrophe at the back, Dilevski looked to pass back to Burch, Mills stood on it, Burch saved well intially from Smith but Lupoli rolled in rebound.
Spurs 0, Arsenal 1
15mins: PENALTY/GOAL. Yeates brought down by O'Donnell, penalty awarded, Barnard sent Taylor wrong way from spot.
Spurs 1, Arsenal 1
35mins: GOAL. O'Hara won big tackle 30 yards out, Jackson picked up loose ball and lashed shot from 20 yards, Taylor parried and Barnard was there to tap home from six yards.
Spurs 2, Arsenal 1
Half-time: Spurs 2, Arsenal 1
60mins: WOODWORK. Jackson picked up loose pass centrally, travelled 20 yards and hit low drive that Taylor tipped onto the post.
63mins: GOAL. Yeates whipped in free-kick from the left that went all the way through to Malcolm, who converted at far post.
Spurs 3, Arsenal 1
72mins: GOAL. Quick free-kick from Jackson caught Arsenal napping, Barnard control and low finish across Taylor into far corner to claim second hat-trick in two games.
Spurs 4, Arsenal 1
76mins: PENALTY/GOAL. Hallfredsson handled Smith's cross, Smith sent Burch wrong way from spot.
Spurs 4, Arsenal 2
Injury time: GOAL. Lupoli picked up Hoyte's pass down the right touchline, cut inside Hallfredsson and drilled into the top corner from 16 yards.
Spurs 4, Arsenal 3
Spurs: Burch, Dilevski, Halfredsson, Mills, Lee, Jackson, O'Hara (McKenna, 83), Yeates, Limbersky, Barnard, Malcolm. Subs: Eyre, Daniels, Barcham, Seanla.
Arsenal: Taylor, Hoyte, Gilbert, Gregg, Djourou, Skulasson, Larsson, O'Donnell (Birchall, 53), Lupoli, Owusu-Abeyie (Bendtner, 73), Smith. Subs: Howard, Muamba.
Lee Barnard bagged a second hat-trick in as many games to inspire our reserves to victory over Arsenal on Monday night.