Champions League: Borussia Dortmund and PSG leave it late; Celtic, Sparta win big

Manchester City and Inter Milan played to a scoreless tie on the second day of the new UEFA Champions League season, but that marquee rematch of the 2023 European final was one of just six games on Wednesday's schedule.

Here are the three biggest takeaways from the day's games.

Kylian Mbappé-less Paris Saint-Germain leaves it late

As the seconds ticked away on the referee's watch during the final throes of PSG's 2024-25 Champions League opener against Spanish side Girona, the packed Parc des Princes crowd could hardly process what was happening.

So what if the Parisians had allowed Kylian Mbappé, perhaps the planet's best player, leave on a free transfer this summer to Real Madrid? Qatar-owned PSG's overarching ambition was and remains to raise this trophy, global soccer's most coveted at the club level, with or without the World Cup-winning French superstar.

PSG still boasts one of the richest and deepest squads in Europe. But it took a 90th minute own goal for Luis Enrique's side to secure all three points on Wednesday against an opponent making its European debut.

Enrique and his players will happily take the victory, no doubt. His locker room is talented enough to make a deep run, at least. The Mbappé-Lionel Messi-Neymar era might take some time to fully leave behind, however, at least if this one is any indication.

Borussia Dortmund, Celtic, Sparta Prague are big winners

It took last year's runners-up Dortmund more than 75 minutes to break through in Belgium against Club Brugge, but the floodgates soon opened after Jamie Bynoe-Gittens finally scored BVB's opening goal with less than a quarter-hour to go.

Bynoe-Gittens iced the outcome with a second for the visitors around 10 minutes later, before substitute Serhou Guirassy converted from the penalty spot to make it 3-0 in the fifth minute of second half stoppage time.

In Prague, Sparta made short work of Austin side Red Bull Salzburg. Finnish midfielder Kaan Kairinen sent his team on its way before two minutes had elapsed and the hosts never looked back in a 3-0 win of their own.

Scottish titans Celtic out-did both with a 5-1 pummeling of Slovakia's Slovan Bratislava. Five different players scored for the Hoops, who won for just the fourth time in their last 33 Champions League outings. USMNT hopeful Auston Trusty made his tournament debut late, replacing fellow Americancenter back Cameron Carter-Vickers.

Highly-touted Man City-Inter match can't live up to the hype

There's little doubt that this was the most hotly anticipated contest of Matchday 1. But despite the likes of Sky Blues striker Erling Haaland and his Nerazzurri counterpart Lauturo Martinez and countless all-world others on the field, the final whistle blew on a goalless stalemate.

It wasn't for a lack of effort on either side. City managed 22 shots, forcing visiting backstop Yann Sommer into several top shelf saves, but finished the match shut out at home for the first time in 42 Champions League games. Meantime, Inter countered with 14 scoring chances of their own. They couldn't make the Citizens pay.

Doug McIntyre is a soccer reporter for FOX Sports. A former staff writer with ESPN and Yahoo Sports, he has covered U.S. men's and women's national teams at FIFA World Cups on five continents. Follow him @ByDougMcIntyre.