The Spitfires secured the bragging rights in Hampshire after a dominant 3-0 win over 10-man Aldershot Town at the Silverlake Stadium.
Aldershot goalkeeper Jordi van Stappershoef was sent off in the 34th minute for a foul on Aidan Barlow and Chris Maguire scored from the resulting free-kick.
The visitors were forced to bring on striker Lorent Tolaj in goal, due to having no goalkeeper on their bench.
Enzio Boldewijn netted a brace in the second half as the hosts coasted to success against their Hampshire rivals.
The Shots had the first effort of the game in the opening minute, when Kwame Thomas had a volley that deflected wide for a corner.
Five minutes later, Boldewijn’s low, driven effort forced van Stappershoef into action, as he tipped the ball wide.
Eastleigh continued to create chances, when Solomon Nwabuoeki placed a shot from outside the box, which was comfortably dealt with by van Stappershoef.
The Dutchman was again called into action when Scott Quigley fired in an attempt towards goal, but the keeper again got down well to prevent the hosts taking the lead.
Tyler Frost blasted a shot towards goal for the visitors just before the half-hour mark that deflected behind for a corner.
The game exploded into life in the 34th minute, as van Stappershoef collided with Barlow as he attempted to lob him and was given a straight red.
Tolaj took the gloves after van Stappershoef was sent off, meaning Aldershot had to play the bulk of the game with an outfield player in goal.
From the resulting free-kick, Maguire put the Spitfires ahead as his shot went in off of the crossbar.
The Shots nearly found a way back into the game when Josh Stokes’ chance went narrowly wide for the visitors shortly before half-time.
In injury time, Tolaj made a comfortable save from a Jake Taylor shot, as the hosts looked to add to their advantage.
Taylor had the first effort of note in the second half, when his shot from outside of the box was charged down by a Shots defender.
Eastleigh almost doubled their lead on the hour mark when Nwabuoeki curled a shot narrowly wide of the mark.
Maguire poked a shot just wide a few minutes later, as Eastleigh continued their search for a second goal.
Moments later, Boldewijn doubled the lead as he headed home from a corner.
Aldershot made a change in goal shortly afterwards, with Tolaj returning to his normal position in attack and Thomas taking the gloves.
The change of goalkeeper made little difference, as Boldewijn netted his second of the game shortly after play resumed.
Charlie Carter tried to catch Thomas off his line with five minutes to go, as the hosts continued to dominate the game.
That was the last attempt of note, as the Spitfires went on to claim their first win of the season in the Vanarama National League.
Eastleigh: McDonnell, Francillette (69), Taylor (c), Barlow (73), Boldewijn, Langston, Hodson, Nwabuokei, Maguire, Quigley, Rutherford
Subs: Scott, Atangana (73), Carter (69), Tshaka, Chalwell
Aldershot Town: van Stappershoef, Mnoga, Harfield, Harries, Rowe (57), Frost, Stokes (75), Glover, Jones (c), Willard (36), Thomas
Subs: Tolaj (36), Scott (75), Burnett, Barham (57), Mullins
Report by Tom Humphrey