After Morgan Whittaker’s 44th-minute penalty was saved by Shrimps goalkeeper Connor Ripley, Argyle grabbed the lead with 20 minutes remaining when Ennis finished at the near post from a Ryan Hardie cross and Cosgrove then added a second after 84 minutes.
Anthony O’Connor pulled a goal back for Morecambe in stoppage time, but Steven Schumacher’s side held out for the win to go two points clear at the summit, replacing Ipswich. The Tractor Boys lost 1-0 at Wycombe, with Brandon Hanlan netting in the 40th minute.
Sheffield Wednesday are two points behind Ipswich in third after they drew 0-0 at Hillsborough with Oxford, who were denied victory when Cameron Dawson kept out a Josh Murphy penalty in the seventh minute of stoppage time.
Devante Cole scored in each half as fourth-placed Barnsley beat struggling Burton 2-0 at Oakwell, the Tykes’ fifth successive league victory. Bolton, in fifth, also won 2-0 at home, beating Exeter, with Conor Bradley and Dion Charles netting in the first half.
David McGoldrick scored a hat-trick as Derby moved into the play-off places with a 4-0 thumping of Forest Green at Pride Park. McGoldrick notched his treble, capped with an 87th-minute effort, after Nathaniel Mendez-Laing had put the Rams ahead five minutes into the contest.
MK Dons won in their first league match since sacking boss Liam Manning, triumphing 2-0 at Portsmouth. Bradley Johnson and Jack Tucker got the goals as the Dons, under Dean Lewington’s interim management, moved up a place to 22nd, swapping spots with Burton.
Charlton, also managerless after dismissing Ben Garner, led at home against Bristol Rovers before being defeated 2-1. Ryan Inniss headed the Addicks in front before the visitors hit back through a second-half brace from substitute John Marquis.
Following the latest round of games, here’s the players who make up the best XI based on ratings from WhoScored. Take a look...
1. Connor Ripley - 9.5
The Morecambe goalkeeper may have been on the losing side at Plymouth but he saved his fourth penalty of the season and limited the hosts to two goals from 13 shots on target. Photo: Martin Rickett
2. Korey Smith - 7.1
The Derby right-back played the entire game as Paul Warne's men picked up a 4-0 win over Forest Green. Photo: Andrew Matthews
3. George Johnston - 8.3
Provided an assist as Bolton won 2-0 against Exeter. Also made two tackles and five interceptions. Photo: Charlotte Tattersall
4. Jack Tucker - 8.1
Scored MK Dons' second goal as they picked up a crucial win over Portsmouth. Photo: Pete Norton