The Blues boss was victorious that day in the Fratton Park dugout as his newly-inherited squad came from behind to snatch all three points from Paul Cook’s Ipswich.
A 32nd-minute James Norwood strike put the visitors ahead, before goals from Tom Naylor and Marcus Harness saw Pompey snatch victory.
After replacing Kenny Jackett in March, Cowley would manage the final 12 games of last term, narrowly missing out on the play-offs on the final day.
A summer of transition was soon to follow and only four members of the Blues’ current team featured in his first match in charge.
We take a look at the first squad Cowley named in his maiden game at the helm at Fratton Park and what those players have gone on to do since.
. League Division 1 - Portsmouth vs Ipswich Town - 20/03/2021 Portsmouth's Marcus Harness celebrates scoring his first goal of the match with Portsmouth's Jack Whatmough
Sunday marks the first anniversary of Danny Cowley's first game in charge of Pompey. Photo: Joe Pepler
. GK: Craig MacGillivray
The keeper played every game under Cowley before failing to negotiate fresh terms in the summer. MacGillivray would go on to join Charlton where he has asserted himself as number one at the Valley keeping 10 clean sheets in 34 league appearances this term. Photo: Bryn Lennon
. RB: James Bolton
Despite starting against Ipswich, Bolton would appear a further five more times for Pompey and later joined Plymouth for an undisclosed fee. However, the 27-year-old has only managed to notch up 11 games for the Pilgrims, with his most recent coming in a 1-0 win over his former employers, after sustaining an ankle injury on the second day of pre-season. Photo: Naomi Baker
. CB: Sean Raggett
Raggett featured in 11 out of Cowley’s first 12 games before the close of last season. The centre-back has been an integral part to Pompey's defensive solidity this season with fans claiming he’s done enough to be Pompey’s player of the season. Photo: Joe Pepler
. CB: Jack Whatmough
The Pompey academy product played eight times in total under Cowley before failing to agree a new contract in the summer. The 25-year-old departed for Wigan where he has since played a key role in the Latics’ promotion push, playing 40 times for Leam Richardson’s side. Photo: Daniel Chesterton
. LB: Lee Brown
The 31-year-old missed a large chunk of the action towards the end of last term after sustaining a hamstring injury against Burton. Cowley opted to continue with the left-back into this campaign but failed to adjust to the new wing-back role. Brown joined AFC Wimbledon in January where he has played 10 times for the Wombles since his arrival. Photo: Joe Pepler
1. GK: Craig MacGillivray
The keeper played every game under Cowley before failing to negotiate fresh terms in the summer. MacGillivray would go on to join Charlton where he has asserted himself as number one at the Valley keeping 10 clean sheets in 34 league appearances this term. Photo: Bryn Lennon
2. RB: James Bolton
Despite starting against Ipswich, Bolton would appear a further five more times for Pompey and later joined Plymouth for an undisclosed fee. However, the 27-year-old has only managed to notch up 11 games for the Pilgrims, with his most recent coming in a 1-0 win over his former employers, after sustaining an ankle injury on the second day of pre-season. Photo: Naomi Baker
3. CB: Sean Raggett
Raggett featured in 11 out of Cowley’s first 12 games before the close of last season. The centre-back has been an integral part to Pompey's defensive solidity this season with fans claiming he’s done enough to be Pompey’s player of the season. Photo: Joe Pepler
4. CB: Jack Whatmough
The Pompey academy product played eight times in total under Cowley before failing to agree a new contract in the summer. The 25-year-old departed for Wigan where he has since played a key role in the Latics’ promotion push, playing 40 times for Leam Richardson’s side. Photo: Daniel Chesterton