Southampton's rich vein of form in the Premier League continued as they beat Burnley 3-1 with two goals from Charlie Austin on Sunday while another promoted side, Middlesbrough, fared just as poorly, losing 1-0 at home to Watford.
With Hull City having crashed 6-1 at Bournemouth on Saturday, the top flight is proving an unforgiving environment for the teams who came up this season with all three now mired at the bottom end of table after posting impressive starts.
Sunday's defeat could have been worse for Championship winners Burnley had goalkeeper Tom Heaton not produced an inspired performance before Austin took his tally to seven goals in six games with a 52nd minute strike and 66th minute penalty.
In between, the impressive Nathan Redmond also found the net as Southampton took their unbeaten run to seven games.
"I've got seven goals in the last six but we are seven unbeaten, that's the main thing," said Austin. "We knew it would be a frustrating afternoon if we didn't score early but once we scored one we kicked on.
"This team will always create chances, it's a dream for any striker. I am in the right place at the right time."
The combination of Austin's instincts and Redmond's pace is paying rich dividends for the Saints, who are brimming with confidence ahead of this week's visits to Inter Milan, in the Europa League, and Manchester City, in the Premier League.
The only downside for Southampton, who are now eighth, was that they conceded their first goal in more than 10 hours of football when Sam Vokes scored from the penalty spot after 72 minutes.
Burnley now sit three places above 17th-placed Middlesbrough, who have yet to win at the Riverside this season and were deservedly beaten in a poor game by a Watford side who always posed the greater threat.
Much of Watford's bite came down the left, where the club's record signing, £12.5 million striker Isaac Success, again proved a real handful having been handed his first start.
Boro were fortunate to reach halftime with 11 men after Antonio Barragan, already on a yellow card, held back the lively Nigerian.
Another probing Success run led to Watford's winner when the ball fell to Jose Holebas, whose 20-yard shot surprised Victor Valdes in the Boro goal. The win moves Walter Mazzarri's side into the top half of the table in 10th place.
"When they scored it was impossible to play. Watford have really experienced players. We need to learn and keep going," said Middlesbrough manager Aitor Karanka, who will be under pressure to check his side's slide down the table.
The Premier League is saving its biggest match of the weekend until last with Liverpool set to host their fiercest rivals Manchester United in what promises to be a compelling Monday night clash at Anfield.
(Reporting by Neil Robinson; Editing by Ian Chadband)