Four sides are two points behind the Silkmen, including Scunthorpe. Bristol R, Wycombe and Northampton are the other three teams, who are all unbeaten with two wins and a draw from the opening three games.
The most impressive result of the day was at Blundell Park, where the Cods chalked up a 5-1 win over a poor Bury side.
Brian Barry-Murphy had given the Shakers a second minute lead, but the home side hit back with two goals from Thomas Pinault and strikes from Darren Mansaram, Ashley Sestanovich and Michael Reddy.
Shrewsbury, in their first season back in the Football League, are the only team still yet to win a point from their opening games.
Full results:
Bristol R 2 Notts Co 1
Cambridge 1 Shrewsbury 0
Cheltenham 1 Leyton O 2
Chester 0 Mansfield 3
Grimsby 5 Bury 1
Kidderminster 1 Darlington 0
Lincoln City 1 Rushden & Diamonds 3
Macclesfield 1 Swansea 0
Northampton 1 Wycombe 1
Oxford 1 Scunthorpe 1
Rochdale 1 Southend 1
Yeovil 2 Boston 0
Highest crowd of the day: 8,225 (Bristol R v Notts Co)