The final ten minutes of an otherwise poor game proved to be the most important as the Wanderers showed great character to come back from behind with just a couple of minutes on the clock remaining.
Bolton had been excellent defensively but they had to be against a bottom of the group Guimaraes team who moved the ball around with surprising pace and fluency in the first half.
Wanderers boss Sam Allardyce had started with Mexican international Jared Borgetti in place of the injured Kevin Davies but the South American was unable to make the necessary impression and was withdrawn in the second half.
Chances during the game where very few and far between and despite the home side having a lot of possession they had been unable to force a clear cut save out of Bolton's Jussi Jaaskelainen until well into the closing period.
Dario Monteiro had the first opportunity for Vitoria on ten minutes but Jaaskelainen was able to cleanly gather the attempt from the Mozambique forward who was earmarked as a potential dangerman in the pre-match build up.
Five minutes later Stelios Giannakopoulos had arguably the best chance of the game as he fired straight at the opposing goalkeeper following a deft flick by lone striker Borgetti.
One of Bolton's leading performers Abdoulaye Diagne-Faye then tried a spectacular effort from near to the centre circle which went way off target as Guimaraes keeper Paiva watched the ball go aimlessly wide.
Kevin Nolan was another player from the visiting side who stood out in the evening and it was his attempt just after the half hour mark which trickled wide of the hosts goal.
Nolan, celebrating his first game as full-time captain, was often found bellowing at his players in an attempt to gee them up in what was overall a very lacklustre first half.
The second half saw an immense improvement from the English side owing to the introductions of veteran midfielder Gary Speed and one time Liverpool front man El-Hadji Diouf.
Prior to the game changing introduction, Jaaskelainen had to be at full stretch to deny an otherwise in-effective Dario Monteiro the chance from giving Vitoria the lead.
Guimaraes had looked to sting the Wanderers through the midfield area and it was the blonde haired number ten Neca who looked to control things prior to the introduction of the old head Gary Speed.
Speed replaced Hidetoshi Nakata on the hour and was immediately joined by Diouf who came on for the frustrated Mexican forward Borgetti who made his way straight down the tunnell area.
Bolton seemed to have quelled the possession play created from the home side and where themselves beginning to get a foothold on the game thanks to the two tactical changes.
With twenty minutes to go Trotters skipper Nolan lashed a shot on the turn into the side netting and was joined a few minutes later by Stelios Giannakopoulos who saw Vitoria goalkeeper Paiva dive at his feet.
The closing stages saw the game come to life due to some slack defending and sleak finishing.
Polish giant Marek Saganowski stooped to head the home side into an undeserved lead after Wanderers defender Ricardo Gardner had drifted in at the far post following a dangerous ball in from the left.
The game looked to be going in the favour of Vitoria and seemed to suggest that Bolton where heading for their first loss in European competition but this was not to be the case as one final throw of the dice saved the Lancashire side.
Ricardo Vaz-Te, a 19-year old striker born in neighbouring Lisbon, came on for Bolton in place of Jay-Jay Okocha in an attempt to snatch an equaliser and the young forward did not disappoint as he produced a superb finish with the outside of the foot following a deft lay off by lively substitute Diouf.
This result almost assures qualifaction to the next phase but the Wanderers will have to make sure when they face Spanish side Sevilla at the Reebok Stadium in the middle of next month.
Bolton Wanderers: Jussi Jaaskelainen, Joey O'Brien, Tal Ben-Haim, Bruno N'Gotty, Ricardo Gardner, Jay-Jay Okocha (Ricardo Vaz-Te), Abdoulaye Diagne-Faye, Hidetoshi Nakata (Gary Speed), Kevin Nolan, Jared Borgetti (El-Hadji Diouf), Stelios Giannakopoulos,
Subs Not Used: Ian Walker, Nicky Hunt, Radhi Jaidi, Khalilou Fadiga
Vitoria Guimaraes: Paiva, Leal Mario Sergio, Attila Dragoner, Guedes Cleber, Pedro Rogerio Matias, Sebastian Svard, Miguel Flavio Meireles, Selim Benachour, Joao Neca (Paulo Almeida), Dario Monteiro (Tiago Targino), Marek Saganowski
Subs Not Used: Miguel Pedro Freitas, Joao Moreno, Pedro Geromel, Jose Zezinho, Lourenco Manoel
Referee: Laurent Duhamel
Attendance: 20,000
Bookmark or share this story with: