Arsenal boss Arsene Wenger: We know it's not over yet

First-half doubles from Aaron Ramsey and Alexandre Lacazette combined with a man-of-the-match performance from Mesut Ozil helped the Gunners build a healthy lead ahead of next week’s trip to Russia.

A disappointing season for the north London club hangs on this competition as it is their only chance of securing Champions League qualification and getting their hands on silverware.

But, despite their three-goal aggregate advantage, Wenger is not taking a semi-final spot for granted.

“We scored some great goals in the first half and at half-time the target was not to concede any more and, if possible, add another one,” said the Frenchman.

“We did the first part of the job in the second half but not the second part of the job.

“On the other hand, it will help us to focus completely in the second game and not think it’s job done, we know it’s not over.

“We have to go there with that right focus and try to win the game.”

After Ramsey’s opener, the Russian side briefly levelled through Aleksandr Golovin’s superb free-kick.

French striker Lacazette, making his first start since January, restored the hosts’ lead from the penalty spot and then completed the scoring following Ramsey’s sensational back-heeled second.

Wenger felt CSKA proved to be tricky opponents and said it was a change for an away team to attack at the Emirates Stadium.

“They played in a very offensive style, we are not used to seeing that at the Emirates in the Premier League,” he added.

“Teams come here, they play in their half and they wait for us and they had a go at us and it was uncomfortable.

“It was a spectacular first half played at a high pace but as well an uncomfortable one for me because they looked dangerous.”

On a largely positive night for the Gunners, there was a sour point as playmaker Henrikh Mkhitaryan was forced off injured in the second half.

Wenger said he was unsure about the severity of the problem but confirmed the Armenian will miss Sunday’s Premier League game with Southampton.

“Mkhitaryan has a knee problem, we don’t know how bad it is,” said Wenger.

“We have to assess it tomorrow morning but he will certainly be out for Sunday.”

CSKA manager Viktor Goncharenko admitted his side were outclassed in London but would not comment on whether they can turn the tie around in the second leg.

“They outperformed us greatly but I’m not disappointed,” he said.

“Of course it’s a very bad result for us but we understood who is playing against us.”

Asked about the second leg, Goncharenko said he was only thinking about Monday’s derby with Dinamo Moscow in the Russian Premier League.

“We can’t jump stages. We shouldn’t speak about the second leg of Arsenal now,” he added.

“A very important match against Dinamo is ahead of us so let’s think about this upcoming match and we’re going to concentrate on it.”