Dimitar Berbatov opened the scoring in the seventh minute with a tap-in from Robbie Keane's cross.
Kalifa Cisse levelled nine minutes later, seizing on an error by Spurs goalkeeper Paul Robinson, who came out to claim Nicky Shorey's free-kick but failed to get power on his punch.
After the break, Ivar Ingimarsson headed in from Shorey's corner to edge the visitors ahead, but Berbatov restored parity with a fearsome drive into the top corner.
"It's obvious we have to score six or seven away from home to get a result," said Reading boss Steve Coppell.
"It's massively disappointing and it feels like there is a hole in your life almost."
Steed Malbranque scored the next equaliser when he curled into the top corner, then Jermain Defoe came off the bench to head in the rebound after Robbie Keane had missed a penalty.
"You have four officials, Keane takes a penalty and Defoe is standing next to him," said Coppell. "It may not have made a difference because he would have to retake it, but the goal should not have been given because the scorer was three yards in the box when he took the kick.
"That gives him a hell of a start over a 12-yard race. I would have got there with three yards head start."
Kevin Dillon, in Reading's backroom staff, appeared to be sent to the stands for his protests.
Berbatov scored his fourth, wrapping up the scoring, when he latched onto a long ball from Younes Kaboul and lashed past Marcus Hahnemann.
"The match was 90 minutes of crazy football," Ramos added. "It was very uncomfortable for me to experience that as a manager.
"There have been a couple of matches where we have been losing but the team always reacts.
"At 4-4, when we scored the fifth and six, we were established up front and deserved to win. It was a great match for the fans to watch but it's not great for a manager to experience."
Coppell blamed individual defensive errors.
"You take the lead three times and score four goals - you play a full attacking part in a game but individual defensive mistakes cost you," he added.