Martin Petrov put Bolton on their way with a 24th minute penalty before a 72nd minute own goal from Billy Jones looked set to hand Wanderers a vital three points at the Reebok Stadium on Sunday.
However, a goal from Chris Brunt put West Brom back in the game and with just 20 seconds to go James Morrison scored the equaliser to hamper Bolton's survival hopes.
The dramatic finish was made even harder to take for Bolton supporters as at almost the same time, QPR grabbed what could be a crucial winning goal against Stoke at Loftus Road.
Third bottom Bolton trail QPR by two points, but their relegation rivals have to go to title-chasing Manchester City on the final day, while Wanderers face an easier trip to Stoke and Coyle insists if they win that they will stay up.
"There's no getting away from how disappointing it was to draw the game, a game we were well placed to win," Coyle said.
"At 2-0 we should have seen it out and had the three points that we craved. My disappointment is that we have allowed that to slip away.
"Having said that the two goals were avoidable, there were a few chances to clear the ball.
"The first one there was a chance to win the tackle in the box and the ball breaks for Brunt. But at 2-1 you're still in control and should see the game out but we've paid a hefty price.
"It is hard to take, but it happened. At that point we were 2-1 up and QPR were drawing, they scored late on so that's how quickly it can change.
"But that's why we know even through all this disappointment that it can all change next week. For it to change, we need to go to Stoke and win.
"We will dust ourselves down and take our medicine and we will pick ourselves up. We have to pick ourselves up. If we win that at Stoke I truly believe we will stay up."
West Brom's fightback dispelled any notion that new England boss Roy Hodgson may have taken his eye off the ball.
The soon to be former West Brom manager did pay tribute to the travelling support by handing out t-shirts before the game.
The shirts read 'Premier club, Premier fans' and were handed personally to the supporters, many already clad in England tops, by the manager.
Hodgson's assistant Keith Downing said: "He was very honoured that there were 4,500 people showing up in England shirts. Supporters have a great warmth for Roy and he wanted to show that feeling back.
"He wanted to do something in the last away game and hopefully everyone will turn up for next week's game."
Downing insists West Brom had to turn in a solid performance at Bolton as they realised other teams were relying on them to get a result.
"We knew the magnitude of the games, particularly for Bolton, so we were very conscious of that," he said.
"It is a testament to the players, we have our own mini targets as a football club so just because of what happened at the start of the week doesn't mean we lose our focus on those."
Source: AFP
Source: AFP