Arsenal are going to have to navigate the tension of the title race with just nine matches left in their bid to win a first league title since 2004.
And when asked by BBC Sport if they have had to go to another level with their work on set-pieces due to the work other sides are doing, Arteta agreed.
“Yes but every team is to be fair,” he said. “Look where they are in terms of the amount of goals that they score.
“We hadn’t scored set-pieces for a few weeks now, but we scored so many in open play.
“Today was an option to score from this kind of situation. We’ve done it so well and we conceded as well.”
Chelsea were starting to grow into the game before Timber’s crucial goal, while they needed goalkeeper David Raya to produce some excellent saves to deny the sixth-placed Blues a point.
“I didn’t think there was an awful lot between the two teams, but Arsenal came out on top and at this stage of the season that’s vital, isn’t it?,” added Arteta’s former Everton team-mate Osman.
“If your strengths are pacy wide men that create things all the time, you give them the ball all the time.
“If your strength is set-pieces, you try to win set-pieces and score from them and they’re very good at it, very effective.
“And ultimately that was that was the difference between the teams, but Arsenal won’t care because it’s another three points.”
According to Osman, Arsenal can be criticised for their style of play and are often compared to title winners of the past but if they win the title, that is all that matters.
“Many people watching want to see beautiful football or purists want to see open play great goals back to front.” he said.
“That’s not how football’s always played. Football is about being effective in both penalty areas, finding a way.
“I think whatever happens in between can be pleasing, can be enjoyable, can be exciting.
“But ultimately, it’s less important than what happens in both penalty areas because that’s where games are won and lost.”