A defeated Arsene Wenger counted the cost of Arsenal's young defenders and a triumphant Jose Mourinho highlighted the value of Zlatan Ibrahimovic's experience to Manchester United on a Sunday of contrasts for the English Premier League managers.
Ibrahimovic, 34, a veteran of top European leagues who made his EPL debut, helped his team's attacking play then scored a superb goal as United opened its campaign with a 3-1 win at Bournemouth.
It was Mourinho's first league game in charge of United, the team owned by the Glazer family which owns the Bucs.
Juan Mata opened the scoring five minutes before halftime and captain Wayne Rooney headed United's second in the 59th before Ibrahimovic rifled home a shot from 27 yards. Adam Smith later scored Bournemouth's consolation goal.
Mourinho was pleased with the win and the performance by Ibrahimovic, with the Swedish forward's role at United expected to go beyond just his performances on the field.
"The first thing I can tell you is that his table for breakfast and his table for meals, he is surrounded by the young ones, surrounded by the kids," Mourinho said. "Luke Shaw, Marcus Rashford, these are the guys that are with him on the table. So he knows what he can be for them.
"But for the team, you have to forget the passport, you have to forget (that he's) 34 years old, because the body and the mentality is not of a 34-year-old guy. So, I think he's at the top of his qualities."
Meanwhile, when traditional powers met at Emirates Stadium in north London — Liverpool owns 18 English titles, second behind Manchester United's 20, and Arsenal is third with 13 — Arsenal was without three of its first-team defenders.
So Wenger gave an EPL debut to 20-year-old Rob Holding, alongside 21-year-old Calum Chambers in central defense.
The experiment didn't work.
A rampant Liverpool came from behind to beat Arsenal 4-3 at Emirates Stadium, ripping Wenger's young defense to pieces in the second half.
Theo Walcott's goal put Arsenal ahead in the 31st minute. But The Gunners were soon overwhelmed; Liverpool leveled through Philippe Coutinho on the stroke of halftime, then raced to a 4-1 lead after the break.
Liverpool's fluent passing and clinical finishing in the second half was too hot for Arsenal to handle. Goals by Adam Lallana, Coutinho and Sadio Mane put the Reds in control before Alex Oxlade-Chamberlain and Chambers scored to give Arsenal hope.
Liverpool manager Juergen Klopp, in his first full season in charge, saw both sides of a sensational result.
"Scoring four goals is wonderful, conceding three is the opposite of that emotion," he said. "It was hard work but a deserved win in the end. It feels brilliant at the moment, actually."
MLS: Razvan Cocis scored off a set piece late in the second half to give host Chicago a 2-2 draw with Orlando City. Cyle Larin and Kaka scored in the first half for Orlando City, which settled for its league-high 12th tie and, at 5-6-12, has more ties than wins and losses combined.
GERMANY: Bayern Munich defeated host Borussia Dortmund 2-0 in the German Super Cup to get new coach Carlo Ancelotti off to a winning start. Arturo Vidal and Thomas Mueller scored in the second half.
Spain: Luis Suarez and substitute Munir El Haddadi scored in the second half to give visiting Barcelona a 2-0 win over Sevilla in the first leg of the Spanish Super Cup. Barcelona hosts Wednesday's second leg.