Arsenal were made to work hard for their place in the FA Cup fifth round before finally beating Brighton & Hove Albion 3-2 at the Amex Stadium.
In-form Oliver Giroud twice put the Gunners in front only to see Brighton hit back, first through Wayne Barnes and then Leonardo Ulloa.
The rested Theo Walcott though came off the bench to give Arsenal the victory five minutes from time, although he needed a huge deflection from Adam El-Abd to score what ultimately proved to be the winner.
Arsene Wenger took the risky decision to rest a number of his in-form stars such as Walcott, Jack Wilshere and Santi Cazorla.
Brighton must have taken heart from that as they started brightly and they almost took the lead in the 15th minute when David Lopez played in Barnes, but Wojciech Szczesny made himself big and made a great save to deny the striker.
The Seagulls were punished for that mistake just a minute later as Arsenal took the lead. They attacked with pace and Lukas Podolski then laid the ball off for Giroud on the edge of the area. There was still plenty for the Frenchman to do but he expertly curled a powerful shot into the corner of the net to give Arsenal the lead.
Brighton did not panic and stuck to their footballing principles. New signing Ulloa had the ball in the net in the 31st minute but he had strayed offside. However, two minutes later Brighton were back on terms.
It was Barnes who got the goal as he benefitted from slack Arsenal defending and indecision from Szczesny to nip in and head a corner directly into the net.
With both teams committed to slick football and a record crowd of 27,113 making an almighty racket it all made for very entertaining stuff and the second-half was as absorbing as the first.
Arsenal started the second-half brightly with Casper Ankergren pushing away a drive from Carl Jenkinson before Podolski curled a free-kick onto the crossbar.
Arsenal were back in front in the 57th minute as Giroud scored another excellent goal. The big striker did superbly well to control a ball over the top from Abou Diaby and just as it looked like he might lose his balance he then smashed home from close range. It was his fourth goal in a week after his double against West Ham on Wednesday night.
Yet it only took Brighton five minutes to equalise. Barnes fizzed in a superb cross from the right and Ulloa dived in to head home a close range debut goal after Per Mertesacker failed to track his run.
Arsenal reacted by bringing on the big guns. Walcott, Wilshere and Kieran Gibbs all came on just as Brighton began to tire. Gus Poyet's side were not helped by the fact that they had to burn two early substitutions: captain Gordon Greer limped off near the end of the first-half and he was joined on the bench by Will Buckley who was forced off at half-time after picking up a knock.
Arsenal began to dominate in the closing stages and finally got the killer goal five minutes from time.
Brighton did a great job defending corners for most of the afternoon but were eventually undone by one as an unconvincing punch from Ankergren found Walcott on the edge of the box – the England international then volleyed towards goal and it seemed to hit El-Abd on the shoulder before nestling into the corner of the net.
Brighton just did not have the energy to really mount a comeback attempt although substitute Craig Mackail-Smith did appeal for a penalty before the end when he challenged for a header with Jenkinson.
Ultimately though, Arsenal did just enough to deserve their fifth round place without the need of a replay as they continue their hunt for a first trophy in eight years.
MAN OF THE MATCH
Oliver Giroud (Arsenal) – The Frenchman got off to a slow start at the Emirates but his two goals here were the finishes of a man full of confidence.
Brighton: Ankergren 6; Calderon 7, Greer 6, El-Abd 6, Bridge 6, Bridcutt 8, Hammond 6, Lopez 8, Buckley 7, Barnes 7, Ulloa 7.
Subs: Dicker 6, LuaLua 6, Mackail-Smith 6.
Arsenal: Szczesny 6, Jenkinson 6, Mertesacker 6, Koscielny 7, Santos 5, Diaby 7, Ramsey 6, Rosicky 7, Oxlade-Chamberlain 7, Podolski 7, Giroud 9.
Subs: Gibbs 6, Wilshere 7,Walcott 7.