Arsenal's Theo Walcott (right) reacts with teammate Gervinho after scoring a goal against Udinese in their Champions League first round qualifier match at Emirates Stadium in London on Tuesday.

Arsenal began life without Cesc Fabregas with a 1-0 win over Udinese on Tuesday in London, although a lively performance from the visitors ensured the Champions League playoff remains in the balance heading into the second leg.

Also Tuesday, Lyon beat Rubin Kazan 3-1, Czech champion Viktoria Plzen won by the same score at Copenhagen. Benfica was held 2-2 in the Netherlands at FC Twente and Austrian side Sturm Graz drew 1-1 in Bulgaria at BATE Borisov.

Theo Walcott scored just four minutes into the first leg to raise spirits among demoralized Arsenal fans following Fabregas' departure, but the injury-hit Gunners could not build on its early advantage.

Only Wojciech Szczesny's saves ensured Arsenal goes to Italy next week with its slender advantage intact as it looks to play in the lucrative Champions League for the 14th consecutive season and guarantee at least US$30 million from UEFA.

"We tended to drop off a bit and there were gaps appearing but we dug in and gave absolutely everything tonight," Arsenal midfielder Aaron Ramsey said. "We believe we're capable of going over there to win. The most important thing is a clean sheet. Our defense was solid."

Ramsey is one of the players expected to fill the boots left by Fabregas' drawn-out move back to boyhood club Barcelona on Monday.

"It's time to move on - he was a great player for the club but now he's gone," Ramsey said. "We just have to concentrate on what we've got here. We believe the squad we've got is very talented."

It was the Wales international who helped to give fans a glimmer of hope for the future by charging down the right flank and floating in the low cross that Walcott turned in past goalkeeper Samir Handanovic at the near post.

"I want to get more goals," Walcott said. "It's a great ball Aaron's played for me. Hopefully the boss will play me up front."

But for all their speedy moves, the Gunners were regularly caught out on the counterattack by an Udinese side playing its first competitive match of the season and chasing a spot in the group stage for the first time in six years

Close calls

Udinese captain Antonio di Natale came close to leveling early on when he curled in the free-kick from 30 yards which looped off the crossbar.

There was another scare for Arsenal after 25 minutes when Alex Song conceded possession deep in Udinese territory, allowing Pablo Armero to storm forward and easily go through the brittle barrier of defenders Bacary Sagna and Kieran Gibbs.

But with only Wojciech Szczesny to beat, Armero was thwarted by the goalkeeper's strong save and the follow-up by Mauricio Isla was blocked by Song, who had raced back into his own half.

At the start of the second half it required a last-ditch intervention by Johan Djourou to block a shot from Di Natale, who was Udinese's most dangerous threat.

A free kick from Serie A's top scorer for the last two seasons was also pushed wide by Szczesny.

"We deserved more than the actual result on the pitch," Udinese coach Francesco Guidoli said. "We didn't take all the chances we had and lost the game, but it's still an open match ... and we built confidence."

The victory also came at a cost for Arsenal with Gibbs coming off at half time with a hamstring injury and his replacement Djourou forced off with the same problem after less than 10 minutes.

Arsene Wenger endured a touchline ban as punishment for a tirade against a referee last season. UEFA told Wenger at half time that he could be contravening its rules by passing instructions to assistant manager Pat Rice on the touchline via first team coach Boro Primorac.