Marcus Rashford repeated his late heroics against Paris St-Germain with a superb winner as Manchester United marked their return to the Champions League with a fine win at the home of last season's beaten finalists.
Rashford's stoppage-time penalty sealed a famous victory at the Parc des Princes 18 months ago and the England striker was again on target to ensure Ole Gunnar Solskjaer's side took maximum points from their opening match in a formidable group.
The visitors had excelled in a first half which saw Bruno Fernandes stroke them ahead with a twice-taken penalty.
But the multiple French champions were far stronger and threatening in the second half and deservedly drew level when United striker Anthony Martial headed into his own net.
David de Gea had to put in a much-improved display in United's goal, making strong saves to deny PSG's superstar duo Kylian Mbappe and Neymar.
And the sides looked set to share the points when Rashford collected a pass from substitute Paul Pogba, rolled away from a defender and fired in off the base of the post from 20 yards.
Solskjaer finds a way
Rashford's penalty completed a stunning comeback in 2019 which all but cemented the case for Solskjaer's temporary reign to be made permanent, turning a delighted Rio Ferdinand - the former United defender turned BT Sport pundit - into a meme in the process.
Solskjaer has not been able to maintain that blistering success since becoming full-time manager, but once again the Norwegian was able to conjure a victory against the odds.
Without captain Harry Maguire and midfielder Pogba, United played a back five - with defender Axel Tuanzebe being summoned from the wilderness and shining on his first appearance of 2020.
Twice the 22-year-old kept stride with the rapid Mbappe and made fine challenges in an impressive display.
At the other end, United's opener came from a more familiar route - Fernandes converting a penalty after Martial was tripped. It was, remarkably, the 27th spot-kick awarded to United since the start of last season.
Fernandes, the captain on the night, actually missed for the second time in three days, but Keylor Navas was clearly off his line before the save and the video assistant referee called it back. Fernandes went the same way; the goalkeeper went the other.
PSG looked far more like their old selves after the break and United had to defend well - but Rashford was guilty of wasting a couple of chances on the counter-attack before his brilliant late winner.
Same old PSG?
The rebuilding of Paris St-Germain has long been aimed solely at European glory - with domestic monopoly tied up years ago - and the run to the final just 58 days ago looked like a key juncture.
Thomas Tuchel's side is packed with blistering talent, but question marks over their consistency have long been raised and this was another frustrating display.
They moved the ball far too slowly in the first half and deserved to find themselves behind, even if De Gea was called into a double save from Angel di Maria and Layvin Kurzawa.
Tuchel moved Di Maria deeper at half-time, sending on Everton loanee Moise Kean up front, and his side were better. De Gea again made a flying save to deny Mbappe after a typically brilliant run, and Kurzawa hit the crossbar with a miscued cross.
Martial gave them a route back into the match when he nodded Neymar's inswinging corner into his own net, but United improved when Pogba came on.
With RB Leipzig - semi-finalists last season - up and running with a win, it is now Tuchel's side who need to click into gear fast just to make it out of Group H.
A 16-year wait - the stats
Paris St-Germain suffered a home defeat in a Champions League group game for the first time in 25 games, since losing 1-3 to CSKA Moscow in December 2004.
Manchester United have scored nine own goals in the Champions League, more than any other side.
Since the start of last season, United have been awarded 27 penalties and scored 22 of them, both highs among sides in Europe's big five leagues (England, France, Germany, Italy and Spain) in that time.
Since his debut for Manchester United in February, Bruno Fernandes has been directly involved in more goals than any other Premier League player (27 - 16 goals, 11 assists).
Fernandes has scored 11 of his 12 penalties for United, more than any other player from Europe's big five leagues in that time.
Anthony Martial is the second French player to score an own goal in the Champions League against French opposition, after Jeremy Mathieu for Barcelona, also against Paris St-Germain, in April 2015.
PSG's Neymar has failed to score in four consecutive Champions League appearances for the first time since November 2013 (his first five games in the competition).