At this stage last season, Arsenal trailed Manchester City by 12 pointsArsenal have played down their chances of winning the Premier League, despite finishing 2022 seven points ahead at the top of the table.
But Arsenal manager Mikel Arteta said his side have room for improvement following a wobble when leading 3-0.
He said the gap at the top of the table "means nothing" if Arsenal slip up, and "our only focus is again to improve".
Arsenal have not won the Premier League since 2004, but just after Arteta's third anniversary as manager they are in pole position to win what would be the club's 14th league title.
Going in to the last Premier League fixture of 2022, Arsenal were buoyed in the knowledge that City had been held 1-1 by Everton at home earlier in the day.
"We knew the result [of the Manchester City game], but the boost is we have to come here and win, and to do that we have to perform at the highest level in this league," Arteta told BBC Sport.
"Tonight we had to have a big performance to win against a really good Brighton side. We had to dig in as well.
"[We have] a lot of things to improve, especially in defending moments. We still have room to improve."
Arsenal and City have played 16 games each so far this season. At the same stage in 2021-22, the Gunners trailed City by 12 points.
"[It] sounds amazing," striker Bukayo Saka told Sky Sports about their current position. "Of course at the start of the season if you asked us if we wanted this, we would bite your hand off. We are really happy."
Saka gave Arsenal the perfect start at Brighton with a goal after just 66 seconds, but the England forward is adamant the team are not looking too far ahead, with the season not even halfway through.
"It is a great opportunity we have - a great place we have put ourselves in," he added. "We are not focusing on that now. We are focusing on the next game because we know how well Newcastle have been playing."
The Magpies, who are third in the league, will visit the Emirates on Tuesday.
