Arsenal manager Arsene Wenger kicks a ball during a team training session in London Colney, Nov 22, 2011. [Photo/Agencies]

LONDON - The irony of Arsenal becoming the first English team to reach the Champions League round of 16 was not lost on manager Arsene Wenger after his team beat Borussia Dortmund 2-1 at the Emirates Stadium on Wednesday to seal top spot in Group F.

The 62-year-old Frenchman, who declared his "love and commitment" to the club before the game, gave a sheepish grin as he admitted "surprise" at Arsenal's stunning turnaround in form following their disastrous start to the season.

"I have to be cautious what I say," he replied when asked if he was astonished that Arsenal had qualified while Premier League rivals Manchester United, Manchester City and Chelsea remained unsure of their places in the knockout stage.

"But I think 'yes' as Manchester United could have qualified (on Tuesday) and everyone expected Manchester City to qualify," he added.

"But it is difficult at this level. I have coached over 150 Champions League matches and every game gives different problems.

"The groups were very difficult for the Premier League teams. The level has gone up a lot and we were in a difficult group, so I am very happy and pleased to see where we have come from."

While the two Manchester clubs and Chelsea all qualified directly for the group stages this season, Arsenal had to come through a tricky qualifier against Udinese in August, when they were playing poorly in the league.

Despite taking only one point from their opening three matches, including an 8-2 thrashing at Manchester United, Arsenal overcame the Italians to reach the competition proper and Wenger said they had recovered well from their poor start.

Arsenal have climbed steadily up the league table on the back of striker Robin van Persie's brilliance and have now qualified for the Champions League knockout stage for the 12th straight season.

Arsenal players celebrate with Robin van Persie (R) after scoring a goal against Borussia Dortmund during their Group F Champions League soccer match at the Emirates stadium in London, Nov 23, 2011. [Photo/Agencies]

Different period

"When we drew Udinese in the qualifier, you could not bet that we would go through as we did. So I am happy because we have come through a very difficult period."

Van Persie was again their match-winner against the German champions, scoring both goals to take his season tally to 17.

The injury-prone Dutchman has stayed fit all year and scored 38 goals in 41 Arsenal matches during 2011 and Wenger could barely hide his delight at the player he appointed skipper after Cesc Fabregas left for Barcelona in the European summer.

"It might not be the obvious choice to make a striker your captain because much of the game is played behind him and strikers focus on their own game," he said.

"But I saw something in him as a captain. He speaks his mind, thinks day and night about football and is completely focused on the game."

And his goals also now give Wenger the luxury of resting some of his team for their final group match at Olympiakos on Dec. 6 while the other English teams will all be playing their strongest sides in a bid to join Arsenal in the last 16.

Wenger, however, said he intended to field a strong side because he wanted to win the match. No-one would blame him if he rested Van Persie though, removing him from the threat of an injury in a game, for Arsenal at least, of academic interest.

Arsenal's Gervinho (L) tackles Borussia Dortmund's Felipe Santana during their Group F Champions League soccer match at the Emirates stadium in London, Nov 23, 2011. [Photo/Agencies]