Playing in the Championship for the first time in eight years following their relegation from the Premier League last season, Wolves are hoping for an immediate return to the top flight.
Cesar Peixoto's first game as Wolves boss was just two minutes away from ending in defeat before Jimenez converted a stoppage-time penalty at Molineux.
Wolves won just three league matches last season in a dismal campaign that fuelled fan protests against Chinese owners Fosun.
Following the surprise decision to hire Peixoto from Portuguese club Gil Vicente to replace Rob Edwards, who was sacked during the close-season, Wolves need a fast start to win back their disgruntled supporters.
The early signs were good as the hosts, featuring debutant Kieran Trippier, took the lead in the 18th minute with their first shot of the season.
Fer Lopez sent a perfect pass behind the Blackburn defence and Zimbabwe midfielder Marshall Munetsi sprinted clear for a composed finish from the edge of the penalty area.
But Tony Mowbray is back in charge of Blackburn for the second time and the experience campaigner watched his side equalise in the 27th minute when Sean McLoughlin cleverly glanced a header past Dan Bentley.
Wolves were stunned by that blow and there was worse to come in the 48th minute as Blackburn forward Andri Gudjohnsen met Dapo Afolayan's cross with a close-range finish.
However, former Fulham star Jimenez came to the rescue in his first appearance of his second spell at Wolves.
Fresh from helping Mexico reach the World Cup last 16, the 35-year-old netted from the spot in the closing seconds after Ryan Alebiosu handled Jackson Tchatchoua's cross.
Wolves are second favourites for promotion behind West Ham and just ahead of Burnley, the other clubs that crashed out of the Premier League last term.
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Spygate shame
West Ham's status is little surprise, given they kept hold of coach Nuno Espirito Santo, who led Wolves to promotion from the second tier in 2018, and influential England forward Jarrod Bowen.
The Hammers start their campaign on Sunday with a trip to Burnley, who are led by new manager Nicky Hayen.
Burnley have won promotion from the Championship in each of the past two seasons they played in the division, both times amassing over 100 points.
With the shadow of their spygate shame still hanging over them, Southampton open at Watford on Sunday.
Southampton were expelled from last season's Championship play-offs after admitting spying on Middlesbrough, Ipswich and Oxford.
Saints boss Tonda Eckert took responsiblity for the scandal, which was exposed when a member of the club's staff was found filming Middlesbrough prior to the first leg of their play-off semi-final.
Southampton beat Middlesbrough but were denied a final showdown with Hull by their expulsion, with the Tigers sealing promotion instead.
Eckert was backed by Southampton despite calls for his sacking but the German could face a ban after being charged by the Football Association.
Middlesbrough, beaten by Hull in the play-off final as last-minute replacements for Southampton, start on Saturday against Lincoln, who are in the Championship for the first time since 1961 after winning promotion from League One.
