Michael Essien, left, and Ashley Cole, right, congratulate Deco, who opened the scoring for Chelsea in the third minute. Photograph: Paul Thomas/AP

You can't win the Premier League season in August, just like you can't win a football match in the opening five minutes. But still there was something ominous about Deco's third minute strike for Chelsea at Wigan today that sealed a 1-0 victory for the Londoners, their second of the season, and shot Luiz-Felipe Scolari's side to the top of the embryonic Premier League table.

After Arsenal's defeat to Fulham yesterday and Manchester United's opening-day strifes against Newcastle, Chelsea have already put down a marker that they are the most ruthless of the bookies' three favourites for the championship. Wigan were bullish and energetic, and will again have been encouraged by the industry of Wilson Palacios in midfield and the "Bulldozer" Amr Zaki up front. But after losing Chris Kirkland to a back injury in the pre-match warm-up, his replacement Mike Pollit's first job was to pick Deco's delicately curved 25-yard free-kick out of his net. Chelsea never hit top gear, but are yet to concede a goal, and Deco, who scored his second of the season, already seems like a crucial component in a title-challenging midfield.

All in all, it was a routine victory for Chelsea, despite intense pressure from the home side at the end of each half. Petr Cech was forced into two good saves by Zaki during Wigan's 20-minute period of ascendancy in the first half, and the Czech keeper helped the substitute Olivier Kapo's 87th minute shot round the post to keep the 90th clean sheet of his career. By contrast, Pollit was flat-footed for Deco's opener, and the strike proved decisive.

Chelsea could also celebrate the return to fitness of Michael Essien, who was named in the starting line-up and lasted the full 90 minutes, twice as long as his manager had intended. The Ghanaian may have been out-muscled and out-worked for long stretches by Palacios, the Honduran who continues to looks like a terrific discovery by Steve Bruce, but Chelsea's midfield – Essien and Deco alongside Frank Lampard and Michael Ballack – is formidable.

Another of Bruce's bargain discoveries, the Egyptian Zaki, threatened to penetrate the Chelsea defence with a number of second-half surges forward from the left. But Ricardo Carvahlo held firm in front of Cech and Chelsea, who destroyed Portsmouth last week, are out the blocks sprinting.