So plenty to hold the interest, just not a result to get excited about.
Here are three things we learned from the encounter.
Peter Cech is actually as advertised
After two uncomfortable performances in his first two starts for Arsenal, marquee signing Petr Cech showed his bona fides against Liverpool. He took a certain goal off the feet of Liverpool front man Christian Benteke, pouncing at the absolute last second, and he stretched every inch of his frame and wingspan to tip Philippe Coutinho's curling effort off the post. Those two saves bailed out a shaky first-half defense and avoided a disastrous result.
Cech also conducted the less eye-catching work flawlessly. He commanded his penalty area, punching or claiming crosses intended for Benteke. Like Wojciech Szczesny in the FA Cup Final, Cech did a lot to negate Benteke's aerial threat.
Cech's positioning was excellent as well, so several threatening shots went right at him. His success kicking away Roberto Firmino's first-half effort owed to perfect positioning and quick feet.
This might have been more activity than Cech has been accustomed to--as 7AM Kickoff noted in his "By the Numbers" piece for Arseblog, Cech hadn't made this many saves in a club match since May 2013. But Arsenal's new number one showed he is the difference-maker many portrayed him as when Arsenal acquired him.
Arsenal feels Mertesacker's absence more than Koscielny's
Most observers consider Laurent Koscielny the more indispensable of Arsenal's two center backs. A few even dubbed him Arsenal's player of the season in 2014-15 for his quickness, timely interventions, and control of opposition strikers.
His partner, the frequently derided Per Mertesacker, seems more vital to the team, though. For one thing, Koscielny has an able replacement in Gabriel, who showed on Monday that he possesses quickness and guile to rival Koscielny's. Gabriel also cottoned to Benteke's approach early on and limited his threat to the Arsenal goal in the second half.
Another reason that Mertesacker is essential is that his deputy, Calum Chambers, hasn't yet developed the calm or comfort with quick decisions that the big German brings. Although the 20-year-old was not caught out of position much, save his one unwise foray forward, Chambers's poor decisions with the ball brought on danger.
It's a huge contrast with Mertesacker. Arsenal's on-pitch captain and World Cup winner not only reduces the danger, he initiates many Arsenal attacks with his incisive passing. Without him, Arsenal struggles to move from defense to attack. In particular, it's hard to use deep-lying midfielder Francis Coquelin as a decoy to drag opposition midfielders out of position. This means more narrow passing lanes from Arsenal's defenders to their attacking teammates.
The consequence is more predictable passes, which Liverpool were primed to pressure. More responsibility and Liverpool attention fell on Santi Cazorla, and Arsenal saw the deception and speed of its transitions reduced. Mertesacker makes a critical contribution to this aspect of Arsenal's play, important to be effective at the Premier League level.
Alexis needs Ramsey's vertical threat
Debate has swirled around Aaron Ramsey's position on the right side of the Arsenal attack. The argument is that he doesn't offer the speedy, wide threat to stretch the opposition defense. Instead, he offers more of a horizontal threat, roaming from right to left between the opponent's midfield and defense.
Ramsey's activity was effective against Liverpool, as it had been against Crystal Palace: He generated four chances and made eight ball recoveries and four tackles.
The issue, though, is that Ramsey's movement from right to left reduces Alexis's liberty. First, when he moves toward Alexis, Ramsey brings defenders with him. And there are already more than a few paying attention to Alexis. Liverpool, for example, surrounded Arsenal's top scorer from last season with a fullback, center half, and midfielder, or with two midfielders and a fullback. This stymied him as he approached the corners of the penalty area where he's most threatening.
It also forced Arsenal to beat Liverpool with several short, quick passes in congested areas. There's little room for error in that approach, because one of many nearby Liverpool players or a slightly misplaced pass can foil the move. On the few occasions when Arsenal can find a way through, the finishing has to be expert. It was not on Monday, just as it wasn't late last season when Swansea and Sunderland held Arsenal scoreless.
If Ramsey were running from the center of midfield, though, he would distract the opposition midfield from its focus on Alexis and offer an option for Mesut Özil to make a decisive pass forward. He's also more of a dynamic target for striker Olivier Giroud's lay-off passes. No doubt manager Arsène Wenger will weigh this need against defense-minded teams.
Extra time: Officials still haven't grasped the offside rule
Ramsey's goal was wrongly waved off. Even if it were a borderline case, isn't the advantage supposed to lie with the attacking player? And if, as Liverpool manager Brendan Rodgers quipped, "his shirt looked offside," it was his shirt sleeve, attached to his arm, not a part of his body that can trigger the infraction.