A night of logic-defying drama saw the Gunners reach the quarter-finals of the Capital One Cup in one of the most astonishing matches this country has seen.
The Madejski Stadium crowd saw Arsenal fought back from 4-0 down to triumph 7-5 in the dying moments of extra time.
Theo Walcott finished with a hat-trick, while Marouane Chamakh scored two, but Russian playmaker Arshavin was also influential, contributing three assists.
"I did not think about when we had to equalise, I just felt that if we had the chance and God will help us, we will make a draw!" he told Arsenal Player.
"He helped us and that's why we scored in the last minute.
"I have lost twice 7-1, once I lost 8-3 and once I won 9-3 and now 7-5.
"But this game was one I will remember always because it was from 4-0 down.
"I don't think anyone here believed that we could come back. But we did it and we deserved to win.
"We showed spirit because you cannot come back from 4-0 down if you don't have spirit."
Arsenal's comeback was given urgency by the arrival of Olivier Giroud from the bench, whose goal capped an energetic performance bristling with intent.
"It's the first time in my career I've played in a game like that," the 26-year-old Frenchman said.
"To be losing 4-0, we were in a very difficult position, but Theo's goal just before half-time made us trust ourselves
"It was important to start well again in the second half, to trust ourselves and stay confident, play through their lines and keep going.
"I tried to do what I could for the team when I came on."
Giroud and Francis Coquelin hurled their shirts into the crowd in jubilation after Walcott's 95th minute strike took the game into extra-time, believing the equaliser meant a replay.
"I thought that in cup games when you drew, there was a replay. Someone told me that!" Giroud said.
"Luckily, I was able to get the shirt back OK - the fan gave it back to me quickly so I could start the game again.
"But after the game, I threw the shirt back into the crowd again after that."
Both teams experienced shellshock, Arsenal after slipping 4-0 behind in pitiful circumstances and then dejected Reading at the final whistle.
Manager Brian McDermott said nothing to his players afterwards, claiming sometimes it is better not to speak, and he must now galvanise them for Sunday's critical Barclays Premier League clash with QPR.
Full-back Nicky Shorey admits the result against Arsenal is hard to accept.
"I don't know what to say. It just seems to be happening to us at the minute and we need to take a look at why," he said.
"I don't really know how to answer how we conceded seven after going 4-0 up.
"I thought we could push for a winner at 5-5, but it's just one of those things."