A young side? Arsenal looked middle-aged on Tuesday night in Romania and Arsène Wenger will have been delighted. Shakespeare wrote of the seven ages of man; a Wenger team has only three.

“It’s the life of your team,” the manager said this week. “They start all enthusiastic and play; after, they go to a level where there is a good balance between being efficient but still playing and then they go to a level where they are only efficient.”

Going unbeaten in 49 league games, as Arsenal did between May 2003 and October 2004 set the Kitemark for efficiency. Only Blackburn Rovers have taken a point from Arsenal this season and the victory over Steaua Bucharest expounded the manager’s theory about the maturing process.

Arsenal were fluent only in spurts but reliably resilient, fashioning a late goal scored by Robin van Persie through a combination of hard work and flair. It was their third 1-0 victory of the season, one behind last year’s total. They top their Champions League group with six points from two fixtures.

It was the team’s ninth successive win, their best run since the “Invincibles” season of 2003-04. That sequence was stopped at ten by a draw with Chelsea at Stamford Bridge, but it should be surpassed this month. Arsenal face three appealing home fixtures: Sunderland on Sunday, then Bolton Wanderers and Slavia Prague before a trip to Anfield on October 28.

Wenger would prefer this vintage remain the Incomparables until they get near the long-term consistency of 2003-04. Still, he lauded his side’s “hunger” on Tuesday and there is a cold-eyed ruthlessness about them that was not visible last season.

“You could see against Derby two weeks ago we were 1-0 up, 2-0 up, and we didn’t change the game,” Van Persie said. “Three-nil, we didn’t change the game. We got to 5-0 and this is how we think about the game and how we’re going to play, I think it is quite special, unique and new.”

The players are growing more adept at blending Wenger’s stylistic principles with pragmatism. Van Persie has scored 39 times for Arsenal but his winner against West Ham United last Saturday was his first headed goal.

The forward is enjoying proving the doubters wrong. “What I saw [in preseason] was a play-togetherness and a great belief, and big, big quality,” he said. “It is not [an opinion] I am going to change.”

Winning is a nice routine to be part of. “If we can stay together we can do amazing stuff in the future. I think we are doing it now already,” Van Persie added. “We are not at the end. We are progressing every week we play. I like the fact that we play together week in, week out and some teams – for example, Liverpool – switch. That’s OK if they choose to do that, but we like to be settled. I know, for example, when Cesc [Fàbregas] has the ball I know what he’s thinking about; I know what I can do. Everyone knows what they have to do. It is very, very important.” And potentially very draining. “Sometimes it is hard because you play Saturday, Tuesday, Saturday or Sunday again,” he said.

At least most legs are young. Of the 2003-04 title-winning team, only Jens Lehmann, Kolo Touré, Gaël Clichy and Gilberto Silva remain. Manuel Almunia – at 30, virtually wizened in comparison with his teammates – appears to have supplanted Lehmann as first-choice goalkeeper but has not asked his manager for confirmation.

“I don’t want any explanation about my situation,” he said. “The only thing I have to do is train, work for the team, I don’t want any words.”