Kieffer Moore scored a first-half hat-trick as Rotherham romped to a 5-0 win against Southend.
The Ipswich loanee scored two goals in as many minutes in the early stages – the second a tap-in after a good team move.
It was 3-0 in the 23rd minute as Joe Newell lashed the ball into the bottom corner and Moore completed his treble in stoppage time.
It was more of the same after the break but the Millers, relegated from the Championship last season, managed just one more goal as Williams tapped in at the end of another fine passing move.
Blackburn, who also dropped out of the second tier last term, slipped to a second straight league defeat as they lost 3-1 at home to Doncaster.
John Marquis, last season’s top scorer in League Two, was given too much time in the area to slot in the opening goal at the start of the second half and James Coppinger added a second from the penalty spot after 67 minutes.
Alfie May made it 3-0 with eight minutes left to play, with Dominic Samuel heading in a consolation for Rovers.
Jack Marriott scored a hat-trick as Peterborough cruised to a 4-1 win at Bristol Rovers.
The summer signing from Luton opened the scoring after six minutes with a low finish and added his second in the 55th minute following good work from Junior Morais.
Former Newcastle defender Steven Taylor made it 3-0, and after Rory Gaffney’s late header for Rovers, Marriott completed his treble deep into time added on.
Oxford made it two wins from two with a 3-0 success against Portsmouth.
Pep Clotet’s men took the lead in the opening moments of the second half when Christian Ribeiro’s low cross was turned in by Wes Thomas, Gino van Kessel made it two and Josh Ruffels’ stoppage-time effort capped a fine display.
Jake Jervis scored both goals as Plymouth claimed a 2-0 win against Charlton, while an early goal from on-loan Newcastle midfielder Sean Longstaff was enough for Blackpool to beat MK Dons.
Devante Cole’s 75th-minute strike earned Fleetwood a 1-0 win at Northampton, while Alex Rodman’s back-post header gave Shrewsbury a 1-0 victory at AFC Wimbledon.
Erhun Oztumer snatched Walsall a 2-1 win against Oldham after Joe Edwards had cancelled out Ryan McLaughlin’s opener for the Latics, while Dominic Poleon scored the only goal as Bradford beat Gillingham 1-0.
Rochdale and Scunthorpe played out a 1-1 draw at Spotland, with the home side taking a 55th-minute lead when a corner was flicked on by Ian Henderson and Steve Davies nodded in.
However, the visitors were level eight minutes later when Duane Holmes slotted the ball under goalkeeper Josh Lillis.
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