Emmanuel Adebayor opened the scoring in the 10th minute and the stage was set for a big performance with the home side struggling to cope with our 4-4-2 system.
But Adebayor was sent off in the 18th minute after catching Santi Cazorla high in a challenge and it all changed.
Arsenal equalised five minutes later through Per Mertesacker and two quickfire goals just before the break from Lukas Podolski and Olivier Giroud put the home side in the driving seat.
Giroud made it 4-2 on the hour but even then, when Gareth Bale drove home for 4-2 with 20 minutes left, all did not seem lost.
We had two chances after that - Bale and Jermain Defoe - to set a few hearts beating faster but Walcott had the final word in injury time.
The team showed three changes from City last weekend. Hugo Lloris was back in goal for Brad Friedel, Kyle Naughton came in for Steven Caulker, injured on England duty and Defoe returned to partner Adebayor in a 4-4-2 system.
It was all going to plan in the first 18 minutes.
Adebayor's strength was clearly causing the Arsenal defence problems and we'd already had a goal correctly ruled out for offside when the Togo striker opened the scoring in the 10th minute.
Jan Vertonghen's pass found both Bale and Defoe breaking through on the left, Defoe took the ball on into the box and aimed low at the far corner. Wojciech Szczesny did well to palm that effort out but Adebayor was there to tap home against his former club.
Adebayor's afternoon lasted another eight minutes after he was shown a straight red for his tackle on Cazorla.
The team maintained its shape with Defoe up front in a 4-4-1 system but the Gunners needed no second invitation to shake off any early anxiety.
Tom Huddlestone did well to block Thomas Vermaelen's close-range effort but it was soon 1-1 as Theo Walcott crossed from the right and Mertesacker powered home a header from 14 yards.
Lloris made a spectacular flying save to deny Giroud and Cazorla flashed a shot over but our 10 men held their own for the next 20 minutes and might have taken the lead again had William Gallas managed to get a touch on Huddlestone's free-kick from the left.
The tide turned completely in the final five minutes of the half.
Arsenal took the lead with a scrappy goal as Mikel Arteta tried to find Cazorla but the ball came off Huddlestone and into the path of Podolski, who turned and hit a bobbler into the corner from 12 yards.
The Gunners then gained a valuable two-goal cushion in first half injury time as Cazorla dribbled down the left and crossed low for Giroud to slide in from six yards.
Andre Villas-Boas changed the system at half-time to 3-4-2 with Michael Dawson and Clint Dempsey on for Naughton and Kyle Walker. Dempsey pushed on to support Defoe with Bale and Lennon remaining wide.
Crucially, Arsenal scored the next goal on the hour as Giroud broke down the left and crossed for Cazorla to bury at the far post.
The lads kept plugging away and it was no surprise when Bale, found in a yard of space by Sandro, drove forward and lashed into the bottom corner with his right foot from 22 yards.
You sensed an edge to the stadium even at 4-2 with 10 men and Bale soon had another chance, flying onto Dempsey's pass down the left and zipping his effort across goal.
Defoe then failed to connect from Bale's deep corner. If only a third goal had found the net...
Instead, the Gunners struck last as Alex Oxlade-Chamberlain broke down the right and squared for Walcott to score from 14 yards.
Arsenal (4-3-3): Szczesny; Sagna, Mertesacker, Koscielny, Vermaelen; Arteta, Cazorla, Wilshere (Ramsey, 71); Podolski (Santos, 80), Giroud (Oxlade-Chamberlain, 86), Walcott. Unused subs: Mannone, Jenkinson, Coquelin, Arshavin.
Spurs (4-4-2): Lloris; Walker (Dempsey, 46), Gallas, Vertonghen, Naughton (Dawson, 46); Lennon, Huddlestone (Carroll, 71),Sandro, Bale; Adebayor, Defoe. Unused subs: Friedel, Livermore, Sigurdsson, Townsend.
Goals: Arsenal - Mertesacker (24), Podolski (42), Giroud (45+1), Cazorla (60), Walcott (90+1). Spurs - Adebayor (10), Bale (70).
Yellow cards: Arsenal - Podolski (80). Spurs - Lennon (45), Sandro (66).
Red card: Spurs - Adebayor (18).
Referee: Mr H Webb.