Gary Speed's injury-time penalty gave Bolton a victory they did not deserve against Premiership newcomers Watford.
Bolton's Nicolas Anelka in action on his debut
Watford had been denied three times by the woodwork, but were heartbroken when Speed scored from the spot after Danny Shittu fouled substitute Idan Tal.
Nicolas Anelka had a quiet debut as Watford were the better side.
Damien Francis hit the post in the first half, then Ashley Young and Malky Mackay struck the bar before Shittu's rash tackle handed Bolton the points.
Watford opened in livelier fashion than Bolton, and defender Nicky Hunt gave the home side a scare after three minutes when he turned a cross from Francis only inches over his own bar.
Francis was the danger man again when he almost put Watford in front in the 19th minute when he picked up Darius Henderson's header and fired a shot against the post.
Little had been seen of expensive new boy Anelka, but he demonstrated his threat when he burst on to a through ball from Kevin Nolan and struck a powerful drive narrowly off target.
Abdoulaye Faye then headed El-Hadji Diouf's corner wide as Bolton finally looked like mounting a sustained spell of pressure.
Anelka showed his pace to burst clear of the Watford defence after 57 minutes, but Ben Foster made a crucial block.
It was the tiring Anelka's final contribution, as he went off to be replaced by former Everton winger Tal.
Young was Watford's most dangerous player, and he almost snatched a winner with nine minutes left, taking a pass from Gavin Mahon and striking the bar with a rising shot.
Marlon King then looked to have wasted a golden chance to seal the points for Watford when he shot wide when through 18 yards out, but the linesman's flag was raised.
Mackay was then a victim of more bad luck for Watford when his header beat Bolton keeper Jussi Jaaskelainen but rebounded to safety off the bar.
And to compound Watford's sense of injustice, they conceded the winner when Shittu's badly-misjudged attempted clearance only resulted in a foul on Tal as he appeared to have run out of options.
Speed lashed the penalty high past Foster to leave Bolton celebrating an unlikely win.
Bolton manager Sam Allardyce
"This was a huge three points for us. It was very disappointing for Aidy Boothroyd because of how well his players played.
"They stuck to their game plan and did it very well and made life very difficult for us.
"Watford had some bad luck, but the Premiership can be a very cruel place and I'm sure Aidy realises that now - but you have to give full credit to his team because they played very well and got no reward."
Watford manager Aidy Boothroyd
"In terms of performance we were unfortunate not to have left with three points.
"To leave with nothing is a bit of a sickener but there were many positive from the game. If we keep playing like that we will be more than all right.
"This result will make us work much harder and when our shots start going in we will be a force."
Bolton: Jaaskelainen, Hunt (Vaz Te 35), Ben Haim, Meite, Fortune, Nolan, Campo, Faye, Speed, Anelka (Tal 70), Diouf (Teimourian 86).
Subs Not Used: Walker, Fojut.
Booked: Nolan, Meite, Fortune.
Goals: Speed 90 pen.
Watford: Foster, Doyley, Mackay, Shittu, Stewart, Smith (Jarrett 71), Mahon, Francis, Young, King, Henderson.
Subs Not Used: Lee, DeMerit, Bangura, Spring.
Ref: M Clattenburg (Co Durham).