Bolton sealed an immediate return to the Championship after relegation last season with a comfortable win over Peterborough at the Macron Stadium.
Midfielder Jem Karacan settled any nerves by volleying them in front from Dorian Dervite's right-wing cross.
Tom Nichols had a goalbound effort blocked by David Wheater as Posh pushed forward in search of a reply.
Wheater headed the second after the break and Adam Le Fondre rifled home to confirm automatic promotion.
Phil Parkinson's experienced side earned their reward for a consistent season, in which they were never lower than eighth in the table and in the top four continuously since 3 October.
They went into the game two points clear of rivals Fleetwood, and with a +8 superior goal difference, and were the first to threaten as Karacan shot wide after Peterborough failed to properly clear Josh Vela's ball in.
The midfielder made no mistake with the second opportunity that came his way, showing superb technique to give keeper Luke McGee no chance as he found the bottom corner.
McGee saved with his legs from Gary Madine to restrict Bolton to a single-goal lead at the interval, but Wheater headed in from two yards after Le Fondre nodded the ball back across goal following a corner.
The second appeared to sap Peterborough's belief and McGee was again in action to beat away a ferocious drive by Mark Beevers, a member of the Millwall side beaten by Barnsley in last season's League One play-off final.
Urged on by the majority of a 22,590 crowd, Bolton opened up the Posh defence again and Vela played in Le Fondre, who fired past McGee into the top corner to spark the promotion celebrations.
Bolton overcome off-pitch problems
Bolton were relegated to League One 12 months ago following a 4-1 defeat by Derby County after a difficult season on and off the pitch, with the paperwork on the club's takeover by Dean Holdsworth and Ken Anderson signed minutes before a High Court winding-up hearing in March 2016.
Despite the change in ownership, the Trotters have had to deal with further difficulties this term, with a public falling out between Holdsworth and Anderson increasing a sense of dysfunction.
Holdsworth eventually agreed the sale of his stake in March, which appeared to put the club back on a stable footing, but Bolton remained under a transfer embargo, imposed in December 2015 for failing to submit accounts, which meant they could not pay fees for new players.
And there were further reports last week of the club being served with a winding-up petition over a £5m debt, with a High Court date set for 22 May, although Bolton say it is a matter for Holdsworth's Sports Shield group.
Right man for the jobPhil Parkinson's side had held second place behind Sheffield United since 13 March
Amid all the off-field issues, Bolton made a shrewd choice when Phil Parkinson was lured from Bradford City to become their new manager last June.
The 49-year-old guided Colchester United to promotion from League One as runners-up in 2006, his first managerial job, and brought Bradford City up from League Two via the play-offs in 2013.
Victories in their first four games and a seven-match unbeaten run set the tone for the season and Parkinson has built the division's meanest defence, conceding only 36 goals in 46 games.
Bolton sold striker Zach Clough to Nottingham Forest in January and, perhaps unusually for a team challenging for promotion, did not have a prolific scorer, with goals this season shared among 19 different players.
However, two of the men Parkinson was able to bring in, Karacan and Le Fondre - one a former free agent on a short-term contract and one on loan - both found the net as Wanderers returned to the second tier along with champions Sheffield United.