On its return to the competition after a five-year absence, the English Premier League club narrowly skirted past Bulgarian minnows Ludogorets 2-1 thanks to an injury-time penalty from captain Steven Gerrard.

After all, this is a club that was 3-0 down to Italian giants AC Milan in the 2005 final and seemingly dead and buried before roaring back to win its fifth European crown on penalties.

A night that started with all the fervor and emotion expected of Anfield on a European Cup night quickly turned into a frustrating one, until Mario Balotelli's 82nd minute strike.

The Reds needed a hero, and as is so often the case, found one in Gerrard, who dispatched a last-gasp penalty after Javier Manquillo had been fouled. Anfield could relax once more.

"It's always nice to win a game, especially when you think you're going to drop two points," Gerrard told ITV. "The game as a whole, we didn't do better than OK and have a lot to learn.

"You've got to give (Balotelli) credit, everyone has been waiting for his first goal. It didn't go his way for a long time but when you've got his ability you only need one chance.

"The key tonight was three points before the performance but at Liverpool we always analyze how we've done and to judge that performance -- must do better."

There had been little to shout about for Liverpool prior to Balotelli's intervention, Adam Lallana coming closest in the opening half.

The home side, who has lost two of its four English Premier League matches this season, were lucky to escape when Roman Bezjak hit the post with 20 minutes remaining.

Then Balotelli's class showed as he pounced on a loose ball inside the area to prod into the far corner in front of The Kop.

Liverpool switched off in the closing stages and when Abalo rounded goalkeeper Simon Mignolet to slide into an empty net, it looked as if the Bulgarians' debut in the competition would yield a famous draw.

But a mistake from Milan Borjan allowed Manquillo to nip in and steal the ball, only for the Ludogorets goalkeeper to bring him down.

Gerrard, whose performance inspired that 2005 comeback in Istanbul, showed composure to slot home from the spot and seal three hard-earned points.

"It was a great night for everyone at club, it's been five years so to get a result was excellent," Liverpool manager Brendan Rodgers told ITV.

"I don't think we're at the level as we were at last year, but there have been a lot of new players come in and it will take a bit of time."

Elsewhere, Real Madrid started its campaign to become the first side to successfully defend a European Champions League title with a comprehensive 5-1 dismantling of Swiss side Basel.

Goals from Cristiano Ronaldo, Gareth Bale, Karim Benzema and James Rodríguez were added to by a Marek Suchy own goal as the Spanish giants bounced back from a derby defeat to Atletico on Saturday.

Atletico, beaten in last season's final by Real, were stunned 3-2 by Olympiakos in Greece, Kostas Mitroglou grabbing what proved to be the winning goal.

Borussia Dortmund, finalists in 2013 when they were beaten by fellow Germans Bayern Munich, got off to a winning start by defeating English side Arsenal 2-0.

Goals in each half from Ciro Immobile and Pierre-Emerick Aubameyang sealed victory in a match that saw Arsenal's new striker Danny Welbeck miss several chances.

Italian champions Juventus beat Swedish side Malmo 2-0 thanks to a brace from Argentina striker Carlos Tevez, while Turkish side Galatasaray drew 1-1 with Anderlecht, from Belgium.

There were also wins for French side Monaco, who beat German side Bayer Leverkusen 1-0, and Russian outfit Zenit St Petersburg, who defeated Benfica 2-0 in Portugal.