The Baggies raced into a 2-0 lead after four minutes through Matej Vydra and Chris Brunt before Stephane Sessegnon made it three after 31 minutes, as the home crowd anticipated more goals against a poor Spurs defence.
However, a Jonas Olsson own goal and a header from Harry Kane gave hope to the visitors, before deep into added-on time, Eriksen struck a 16-yard effort into the top corner to cap a superb fightback from his team.
Below, Sports Mole assesses whether a draw was a fair result at The Hawthorns.
West Bromwich Albion
On target: 5
On target: 8
Was the result fair?
On reflection, you have to say that a draw was probably a fair result. West Brom were excellent for the opening half hour and fully deserved their 3-0 advantage. However, once they had fortuitously pulled a goal back, Spurs were the better of the two teams and although they struggled in front of goal, it's hard to begrudge them their equaliser, which was terrifically taken by Eriksen.
West Bromwich Albion's performance
Pepe Mel will be delighted with his team's attacking display, but they look poor in defence and if they are relegated at the end of the season, the Spaniard will reflect on opportunities like today where they could have opened up a sizeable advantage over their rivals. The former Real Betis coach is getting his message across to his strikers, but they cannot go into every game trying to score three goals to earn a point. It's a point gained in their attempts to stay up, but in reality, it's two dropped.
Tottenham Hotspur's performance
When his team fell three goals behind in the first 30 minutes, Tim Sherwood was probably an hour away from the sack. They were being opened up at will by the home side and on another day, it could have been a lot worse for them. However, they got the bit of luck that they needed, and after a stern half-time dressing down, they were fantastic after the break and Eriksen's brilliantly-taken goal was fully deserved.
Sports Mole's man of the match
Christian Eriksen: There were moments in the game where a few players could claim to be rated as the man of the match, but Eriksen gets it for his last-minute goal. He drifted in and out of the game, but Spurs paid their money for moments like the one that saw him score in front of the visiting supporters.
Emmanuel Adebayor is the clear, and deserving, winner of gaffe of the day. He had the opportunity to halve his side's deficit after 15 minutes, but his effortless approach to the spot kick wasn't necessary, and if his team never fought back in the fashion that they did, it could have contributed to his manager being removed from his position.
Neil Swarbrick was far from perfect this afternoon, but he got the big decisions correct. He rightly awarded Tottenham a penalty during the first half, before cautioning Danny Rose for diving in the second 45 minutes. Questions may be asked about his reasoning to add six minutes of added-on time, but overall, the official can be pleased with his afternoon's work.
West Bromwich Albion: The Baggies travel to Manchester City in their next game before they host West Ham United.
Tottenham Hotspur: Tottenham host Fulham next weekend before making another journey to the Midlands to face Stoke City.