Wanderers let two points slip from their grasp as Portsmouth fought back to grab a share of the spoils in a game of two halves at the Reebok.
Strikes within the space of three minutes from pairing Ivan Klasnic and Kevin Davies gave Wanderers a 2-0 lead at half-time.
But Pompey staged a valiant revival in the second-half as Aruna Dindane notched a brace to grab a point for the South Coast club.
Wanderers and Kevin Davies suffered even more frustration in dying seconds when the skipper saw a header bounce back off the post.
The result leaves Bolton still occupying 14th spot with Owen Coyle waiting for the outcome of Sunday's game between Liverpool and Burnley for confirmation on Premier League survival in the 2009/10 campaign.
With Hull City falling to defeat against Sunderland, should the Clarets lose or draw at Turf Moor then Wanderers stay in the top-flight will be extended to ten successive seasons.
As with the conditions, Wanderers started brightly, continuing where they left off at the Britannia Stadium seven days earlier.
Once again it was Matt Taylor in the heart of the action as the former Pompey man struck a fierce long-range free-kick, which could only be parried by David James. Gary Cahill was first to react but the post denied the central defender from notching his first goal since returning from a blood clot.
James made amends for his slight fumble on the set-piece by making two fantastic saves to deny Taylor and Klasnic, all within the opening ten minutes.
Taylor, who had scored against his former club in the corresponding fixture at Fratton Park back in September, firstly saw a well directed header turned away by the England goalkeeper before Klasnic worked the 39-year-old with a skidding right-foot effort after controlling Weiss's cross with precision.
The opening exchanges were proving to be a tale of two goalkeepers as up the other end, John Utaka brought a smart low save out of Jussi Jaaskelainen with an effort from the edge of the area destined for the bottom corner.
And the Finn needed to be alert when Anthony Vander Borre attacked from right-back, testing the Bolton stopper's reactions from a tight angle.
Despite Pompey's advances, Bolton had looked the more threatening team and fully deserved to take the lead with 26 minutes played.
Ivan Klasnic was the man on the end of Jack Wilshere's delicate near-post cross as he nodded the ball across goal and into the back of the net to score for the first time in 2010.
The lead was doubled two minutes later when Kevin Davies tapped home from point-blank range. Although the skipper's name will go down on the scoresheet, it was the lightning speed and skill of Weiss that carved out the opportunity.
The winger nutmegged young Leonard Sowah, eased past him with his blistering pace before putting the ball on a plate for Davies to convert for the eighth time this season.
Manger Owen Coyle had handed Klasnic and Weiss starting berths following the second-half showings at the Britannia Stadium seven days earlier, and he couldn't have asked for anything more from the on loan duo.
Pompey had been stunned by Bolton's quick-fire double, but they came within a whisker of halving the deficit when Tommy Smith rattled the post with a 30 yard effort. Jaaskelainen was beaten and thankfully the woodwork came to his rescue.
There were further efforts from Gary Cahill and Fabrice Muamba before the interval, the latter of which brought ironic cheers from the home fans when the ball landed way off target.
Avram Grant drafted Fred Piquionne into the action at half-time as he looked to bolster his attacking options and the Frenchman played a big part in Pompey reducing arrears ten minutes after the restart.
Matt Taylor had come within a few inches of killing-off the contest when he prodded wide following great build-up play from Muamba - a moment which proved pivotal - but minutes later Portsmouth were well and truly back in the game.
When Jack Wilshere lost possession midway in the Portsmouth half, the visitors embarked on a swift counter-attack, which resulted in Dindane scuffing the ball into the back of net after being expertly picked out by Piquionne.
And the man on loan from Lens brought his side back on level terms on 67 minutes when he again found himself well positioned inside the penalty box.
John Utaka got goal-side of Cahill, and having reached the byline, he stood a cross up for Dindane, who couldn't miss from just a few yards out.
The game had been turned on its head and as a touch of anxiety swept across the Reebok, Chung-Yong and Johan Elmander were thrown on by Owen Coyle
Davies sliced wide, Knight mis-kicked when unmarked 15 yards from goal and Wilshere struck a venomous volley into the arms of James from well outside the area as Bolton pressed and pressed in the final stages.
And deep into stoppage time, Kevin Davies saw a header strike the base of the post with James unmoved.
That incident typified the way events transpired in the second-half as Portsmouth held on for a point, much to the delight of the 400 or so supporters who had made the long journey up from the South Coast.
Bolton: Jaaskelainen, Steinsson, Cahill, Knight, Robinson, Taylor, Wilshere (Mark Davies 82), Muamba, Weiss (Chung-Yong 70), Kevin Davies, Klasnic (Elmander) (Subs: Al Habsi, Samuel, Ricketts, Cohen)
Portsmouth: James, Vanden Borre, Rocha, Mokoena, Sowah, Brown, Yebda (Piquionne 46), Hughes, Dindane, Utaka, Smith (Subs: Ashdown, Ward, Ritchie, Bouba Diop, Mullins, Wilson)