Pep Guardiola and Jose Mourinho greeted each other as cordially as possible -- considering the two have had their spats over the years -- but it was the end-to-end action on the pitch that ended in a 2-1 Manchester City defeat over hated rivals Manchester United that will deservedly command the post-game analysis.
In a match defined by its endless blistering pace, Kevin De Bruyne opened the scoring in the 15th minute with an impressive breakaway goal that caught United defender Daley Blind asleep at the wheel.
The Belgian, who dominated the United defense throughout the first half was also involved in City's second goal, firing a shot which ricocheted off the post straight to the feet of Kelechi Iheanacho who scored what will likely be his easiest goal of the season.
"It's a dream come true to play in a Manchester derby, and to get the winning goal, so I am very, very happy," said the 19-year-old Nigerian striker, who appears to have solidified a spot in Guardiola's starting 11. "I didn't anticipate the shot, actually, but I'm happy it came off me."
Wayne Rooney, who looked a step too slow for the lightening pace of the match, vented his frustration by shoving Guardiola midway through the first half. The manager apparently held the ball a second too long for Rooney's liking after it rolled out of bounds. The two shook hands afterward, however, as play resumed.
Minutes later, a mild Rooney free kick which floated outside of the six-yard box drew City's Chilean keeper Claudio Bravo into making a calamitous mistake by coming off his line. Although Bravo grazed the ball, he couldn't control it, and it bounced straight to Zlatan Ibrahimovic who casually thumped in his fourth goal of the season.
United's second half substitution of Marcus Rashford for Jesse Lingard had an immediate impact, with the 18-year-old using his fresh legs to challenge City's defenders with a series of near-misses, one which bounced into the goal off Ibrahimovic, who was loitering offside.
Nerves seemed to have gotten the better of Bravo for most of the day, as he committed what could easily have been a cardable offense by launching into a studs-up challenge with Rooney in the penalty box early in the second half. Luckily for City, referee Mark Clattenburg looked the other way.
Clattenberg returned the favor to Rooney in the 77th minute, as the United captain made a clumsy challenge of his own that deserved a yellow card but elicited nothing more than a free kick wasted by De Bruyne.
Rooney finally was given a yellow for a ridiculous tackle on Bravo, after the keeper had already cleared the ball away in the 81st minute. The two familiarized themselves to one another by exchanging words, and will undoubtedly renew their budding rivalry down the road.
Guardiola came to his goalkeeper's defense, saying Bravo's play was "one of the best performances I've ever seen."
"At the end, football is how you react after mistakes," Guardiola told Sky Sports.
Ibrahimovic had one last chance to equal the score in the third minute of extra time, but couldn't convert, delivering Mourinho's first loss at the helm of United. City, meanwhile, have won all four of their league matches to go on top of the Premier League table with a perfect 12 points.
"We started the game bad. We stared the game with players well below their normal levels, in terms of their concentration and mental ability to play a game of this speed," Mourinho offered in post-match comments to Sky Sports. "The team paid for it."
The pre-match hype loomed over the event as soon as the new Premier League schedule was announced in June. That's because for the first time in recent memory, the derby featured two headliners in the managerial position. Pep Guardiola has long been announced as the new City manager, and Mourinho had been confirmed as the new Manchester United manager in May.
As managers, the two have achieved a combined total of four Champions League titles (two each) and 14 domestic league trophies (Mourinho with 8 and Guardiola 6).
Though they had met 16 times in the past, with Guardiola winning eight matches and Mourinho just three, it was Mourinho who prevailed in the two-game series as manager of Inter Milan against Pep's Barcelona team in the 2009-10 Champions League. Inter would go on to win the tournament.
But their most famous -- or infamous -- matchup occurred in the second leg of the 2011 Supercopa, when Mourinho's Real Madrid side lost to Barcelona. The physical affair saw both sets of benches empty in extra time, while Mourinho was caught on camera poking Guardiola's assistant Tito Vilanova in the eye.
More Premier League results
A controversial penalty awarded to Arsenal for a José Fonte foul on Olivier Giroud at the very end of regulation gave the Gunners a 2-1 win over Southampton at the Emirates.
West Ham managed to blow a 2-0 lead over Watford, losing 4-2 at the Olympic Stadium. The win was Watford's first in the Premier League this season.
In his first appearance for Tottenham this season, Korean winger Son Heung-min scored twice, as Spurs cruised at Stoke City 4-0.
Hull City drew 1-1 at Burnley, while Crystal Palace won 2-1 at Middlesbrough. Bournemouth beat West Brom 1-0 at home.
In Saturday's late match, Liverpool delivered a 4-1 defeat to a frustrated Leicester side at Anfield behind Brazilian Roberto Firmino's bookend goals.
Liverpool sit in fifth place, tying four other teams with seven points. Meanwhile, defending title holders Leicester are in 15th place, eight points behind leaders Manchester City.