Arsenal and Liverpool emerged victorious from two of the Premier League's fiercest rivalries with wins over Tottenham Hotspur and Manchester United respectively on Sunday.
Arsenal prevailed over big-spending Spurs 1-0 thanks to Olivier Giroud's third goal in as many matches, while Daniel Sturridge matched him in the scoring stakes as The Reds also won 1-0 on the day the club celebrated the 100th birthday of their renowned former manager Bill Shankly.
Liverpool sit top of the Premier League with nine points from three matches, two ahead of Chelsea.
Manchester City, Arsenal, Stoke City and Spurs are on six points, with United two further back on four.
Spurs have spent heavily in the transfer window in anticipation of the world record sale of Welsh winger Gareth Bale to Real Madrid, while Arsenal have only brought in Yaya Sanogo and Mathieu Flamini on free transfers.
Bale's transfer to the Spanish club for 100 million euros ($131.86 million) was confirmed shortly after the match.
Spurs started brightly but Arsenal, however, looked the more cohesive side and were rewarded after 23 minutes when Tomas Rosicky and Theo Walcott combined to set up Giroud at the near post.
The goal failed to subdue a frantic start as both sides took advantage of gaps in the midfield, with Andros Townsend, Walcott and the impressive Aaron Ramsey all having opportunities.
Both teams pressed in search of further goals as the match progressed, but neither were able to find the crucial touch, with Spurs in particular indebted to goalkeeper Hugo Lloris, who made several fine saves.
"I was (relieved) because in the end we did hang on and protected our score because we could not get the second goal but overall it was an intense game," manager Arsene Wenger told Sky Sport.
"Their goalkeeper was their best player which shows you the chances we had. We had to dig deep to win in the end."
It was a sweet victory for Arsenal who have recovered from their shock 3-1 defeat by Aston Villa on the opening day of the season with two successive wins, and could help silence some of the critics hitting out at Wenger's lack of action in the transfer market.
"We had opportunities in the first half, they also started strong but I think we came back into the game very positively," manager Andre Villas-Boas said, also acknowledging the new signings needed time to settle in.
"The second half was very strong from us, it was a difficult encounter but I think we deserved something in the second half but Arsenal were clinical in front of goal. That they finished with four full-backs on the pitch at the end shows how much they wanted to hang on to the result."
STURRIDGE ON TARGET
At Anfield Liverpool honoured Shankly in the best possible fashion when Daniel Agger got the better of Rio Ferdinand from a corner and Sturridge, celebrating his 24th birthday, reacted sharply to nod the ball home from close range in just the fourth minute.
Champions United, without striker Wayne Rooney after a training-ground incident left him with a bad cut on his forehead, rarely threatened to equalise despite dominating possession.
David Moyes's first competitive defeat as United manager continued his poor record at Anfield where he failed to win in 12 attempts when he was in charge at Everton.
"It is a great win for our belief, last season we drew too many of the big games and we lost both times to Manchester United, but today was another marker for us and since January our form has been very, very good," Liverpool manager Brendan Rodgers said.
In a frenetic start Liverpool looked the more dangerous side with Philippe Coutinho continuing his impressive start to life in the Premier League by causing problems down the left, while United struggled to impose any authority in the middle of the park, where Tom Cleverley and Ryan Giggs endured difficult afternoons.
United stepped up their efforts after the break, but with Agger and Martin Skrtel strong in the Liverpool defence United's best openings were limited to a ferocious strike by Portuguese substitute Nani which was well blocked by Simon Mignolet and a late chance for Van Persie which he sent well wide.
"I thought we played really well," Moyes said.
"We had long periods of the game but couldn't score. Apart from the lapse in concentration for their goal, we played well."
In the other early kickoff, Swansea City picked up their first points of the season with victory over West Bromwich Albion, who lie bottom of the table with a single point and no goals scored.
Ben Davies opened the scoring in the 22nd minute with a classy side-foot volley after being set up by Pablo Hernandez who sealed all three points in the 83rd minute, capitalising on good work from compatriot Michu.