Arsene Wenger admitted his "regret'' that Arsenal had not finished off Roma in their Champions League last-16 clash at the Emirates Stadium.
A first-half penalty from Robin van Persie gave the Gunners a slender advantage to take back to Italy in a fortnight's time.
However, the tie should have been over but for some poor finishing as both Nicklas Bendtner and Emmanuel Eboue missed golden chances to extend the advantage.
Nevertheless, the Gunners boss - whose side had drawn their last three Barclays Premier League games 0-0 - was confident of progress to the quarter-finals.
"That is the regret we have tonight. I am happy with our performance, but of course there was room to score more goals,'' Wenger said. "From tonight we know we can create chances. You never know what a good result is in the European Cup.
"One of the positives is we didn't concede a goal. It's put us in a position where we know we need to attack over there. If we score once that should be enough.''
Arsenal - who are now unbeaten in 14 games - again had plenty of possession and played at a high tempo, but were not able to find a telling pass to unlock the visitors' stretched backline.
"Our pace gave them problems in the first half. In the first 20 minutes of the second half, we had one chance after another,'' Wenger said. "There was room to score more.
"We lack maybe a bit of spontaneity because we want to do so well. I believe the games are locked in the Premier league because teams refuse to play. When the teams don't come out there is no space.
"In this kind of game both teams take the initiative when they win the ball back.''
Wenger, though, knows the job is only half done.
"The next game will of course be an interesting one because they will throw much more forward,'' said the Arsenal boss. "We have three more games between this tie and the second leg. At the speed we lose players it can be a difficulty for us.''
The second half opened in farcical fashion as Roma kicked off when Arsenal only had nine men on the field.
William Gallas and Kolo Toure eventually dashed from out of the tunnel, with the Ivory Coast defender running straight onto the pitch - and being promptly booked by Danish referee Claus Bo Larsen for entering the field of play without permission.
Wenger revealed: "It's explainable by the fact that Kolo always goes out last. He waited for William, but didn't know William had treatment. He didn't know the game had started without them. He was putting on his boots.
"I don't know if it is superstition. It is our fault. You have to be ready when the bell rings.''
Roma coach Luciano Spalletti accepted he could have little complaint with the result.
The Serie A side had looked dangerous on the break in spells.
Marco Motta forced a fine finger-tip save from Gunners keeper Manuel Almunia during the first half.
"Probably Arsenal has done better than us and they won with merit. I think it is a fair result,'' said Spalletti. "Arsenal were different from what I saw in the last games. ''We played a good pace, running with intensity and they gave us a lot of difficulties.
"We weren't good at managing the situation. In the first half Arsenal controlled the game. When they play at this pace and they are so creative and fast and try to go forward without holding the ball long, it results in a difficult situation.
"We haven't created much, but in the second half we were more in the match.''
Spalletti, however, maintains the tie is not yet over.
"I feel confident to say we have the same chances as Arsenal, maybe 49 per cent for us and 51 for Arsenal because they have the goal,'' he said, "But we can create chances and I am sure it will be a completely different game in the second leg.''