By Mike Collett

LONDON (Reuters) - Arsenal gave Sevilla a lesson in what the Champions League is all about when they beat the UEFA Cup holders 3-0 in their opening Group H match on Wednesday.

Arsenal dominated almost from the first kick and sealed it with goals from outstanding midfield matador Cesc Fabregas after 27 minutes and Robin van Persie in the 59th.

Substitute Eduardo da Silva slid home the third in stoppage time just minutes after coming on.

It was Sevilla's first match at this level since they played in the old European Cup exactly 50 seasons ago and despite playing their usual high tempo game, they rarely troubled the home side.

Fabregas's long-range strike appeared to be going wide until it took an emphatic deflection off Julien Escude and went in, while Van Persie scored from close range after Bacary Sagna flicked on a Fabregas free kick.

Eduardo sealed a superb performance with a goal deep in stoppage time just minutes after coming on as a substitute.

"We have made almost the perfect start to the season," said Arsenal coach Arsene Wenger whose team are top of the Premier League and now top of Group H.

Slavia Prague beat Steaua Bucharest 2-1 in the other match in the group.

"I am very pleased with the spirit and the display. We were playing against a very good side. We were a bit lucky perhaps on the first goal, but we controlled the game and never really looked like being under threat in the second half.

"Maybe 3-0 is a bit flattering to us, but we look more mature tactically for 90 minutes than we did a year ago."

CLINICAL FINISHING

Sevilla coach Juande Ramos said his team were punished by some clinical Arsenal finishing.

"It is a big step up from the UEFA Cup to the Champions League. You are playing against stronger teams and Arsenal were excellent. They defended well and they took their chances.

"I did not think we were too bad. But they killed us off."

Although Sevilla looked dangerous when they broke, Arsenal had the lion's share of possession. Fabregas kept Sevilla hemmed in their own half for most of the opening 45 minutes.

Sevilla's best chance came three minutes before the break.

Striker Fredric Kanoute, who scored three times against Arsenal while he played in England for West Ham and Tottenham Hotspur, powered in a blistering drive -- only to see Manuel Almunia defy him with a superb dive to his left.

Most of the scoring chances were at the other end, starting with van Persie's run and shot which Andres Palop parried after 12 minutes.

Mathieu Flamini tested Palop with a fiercely hit shot soon after and again the goalkeeper only parried, taking a knock from Emmanuel Adebayor who was quick to follow up the loose ball.

With Aleksander Hleb and Tomas Rosicky cutting in intelligently from the wings, Sevilla were struggling to cope with the home side's forays and did well to restrict Arsenal to just one goal by halftime.

They went close a couple of times after the break but the majority of the 59,992 fans were more than pleased with the outcome as Arsenal extended their unbeaten run to 15 matches in all competitions since losing to West Ham on April 7.