Walcott's ton of relief for Gunners
Sutton United 0 Arsenal 2
In the end, everyone got what they wanted from this bizarre football carnival played on plastic.
Arsenal won the match, diluting bitter memories of last week's nightmare in Munich. They will be in the quarter-finals and, hosting Lincoln City, they can start to think about their Wembley semi-final two months from now.
Sutton United will go no further in the FA Cup but this evening went perfectly for them beyond that. They kept their pride, holding Arsenal to a narrow 2-0 win for which they had to work very hard indeed.
They gave the best possible account of themselves, enjoying a spell of pressure in the second half which the Gunners did not enjoy. They put on a perfect cup show, happy and spirited, the type of evening this club was not built for and will never have to put on again.
But the circus rolled through smoothly, and for the last 20 minutes they even got to see Alexis Sanchez play. He will certainly not be back.
The hosts' back-up goalkeeper Wayne Shaw will be, though. He entertained television viewers by gleefully tucking into a pie while on the bench.
Of course, Arsenal knew that this was not going to be like any other game they had played before. Their coach did not trundle through the crowds outside until 70 minutes before kick-off. When the players finally came out to warm-up, they had to fight for space with mascots, onlookers, balloons and autograph-hunters.
When the match begun, Arsenal had to get used to a wet, skiddy, bouncy surface, which had been soaked through before kick-off, against a team far more used to it than them. Sutton played with all the honesty and energy you would expect, leaping into some tackles Michael Oliver would have carded in the Premier League.
Arsenal knew that this was not going to be easy, especially with former players Roarie Deacon and Craig Eastmond driving forward, causing panic.
There was never much flow to Arsenal's attacks, but they did have better players and after 26 minutes, that gave them the lead. Arsenal broke down the right, moving it to Lucas Perez. He was in a crossing position but he cut back in on his left and whipped the ball at goal. It flew past Theo Walcott and into the bottom corner.
But that would not itself kill the contest. Arsenal were still capable of making their own errors and when David Ospina kicked straight out to Adam May, he was fortunate not to be punished. The Gunners went in at the break with plenty to do.
What Arsenal really needed to do was to show their class, and that is what they managed. With Alex Oxlade-Chamberlain on for the struggling Mohamed Elneny, they played with more zip and finally started carving Sutton open.
With swift movement and passing, finally at home on the surface, they started to find shooting positions and soon enough, 10 minutes after the restart, they doubled their lead.
Oxlade-Chamberlain started the move, finding Alex Iwobi who played in Nacho Monreal at the far post. He drove in a low cross and Walcott swept it in at the far post for his 100th goal for the Gunners.
Maybe the 2-0 deficit relaxed Sutton, but they started to cause more problems than ever before. Maxime Biamou shot straight at Ospina and Jamie Collins thundered a header over the bar. Then, closest of all, Deacon smacked a 25-yard shot onto the crossbar.
But that pressure dissipated as the Sutton players tired. Arsenal brought on Sanchez, to the applause of the crowd, and the end was an exhibition in whether one of the best players in the world could score at a team trying to stay in the National League. He could not, but it did not matter. Everyone had got what they came for, although for Arsenal, at least for a while, the show will go on.
Sutton: Worner, Downer, Collins, Beckwith (Spence, 70 mins), Amankwaah, Bailey, Eastmond, Gomis, Deacon, May (Hudson-Odoi, 71 mins), Biamou (Fitchett, 82 mins). Unused subs: John, Monakana, Tubbs, Shaw.
Arsenal: Ospina, Gabriel, Mustafi, Holding, Monreal, Elneny (Oxlade-Chamberlain, 46 mins), Xhaka, Lucas Perez, Reine-Adelaide (Maitland-Niles, 74 mins), Iwobi (Sanchez, 74 mins), Walcott. Unused subs: Debuchy, Gibbs, Mertesacker, Martinez.