The 3-3 stalemate at Hillsborough took many by surprise given the Owls’ transfer business during the summer and the 4-0 win they secured against the Blues on the final day of last season just three months ago.
But in truth, Pompey will have been disappointed with just a draw as Danny Cowley’s new-look battling side came within minutes of securing a huge victory on day one of the new term.
The Blues, nevertheless, put down an important marker for the challenge ahead and will no doubt have made others in League One sit up and take notice.
Cowley admitted before a ball was kicked in Yorkshire that he was happy to go into the season under the radar.
Well, that won’t happen now given the result at Hillsborough.
But what do the bookies’ think now about the race for promotion from the division and, in particular, the Blues’ chances of reaching the Championship?
Well, we checked in with SkyBet to see exactly just that with day one of the new campaign now out of the way.
Here's what he discovered.
13. Charlton - 8/1
IN: Eoghan O'Connell (Rochdale, free), Mandela Egbo (Swindon, free), Joe Wollacott (Swindon, free), Ashley Maynard-Brewer (Gillingham, loan), Conor McGrandles (Lincoln, free), Steven Sessegnon (Fulham, loan), Jack Payne (Swindon, free). OUT: Ben Purrington (Ross County), Josh Davison (AFC Wimbledon, undisc), Chris Gunter (AFC Wimbledon, free), Conor Washington (Rotherham, free), Adam Matthews (Omonian, free) Photo: Andrew Redington
14. Plymouth - 11/2
IN: Matt Butcher (Accrington, free), Mickel Miller (Rotherham, free), Finn Azaz (Aston Villa, loan), Bali Mumba (Norwich, loan), Morgan Whittaker (Swansea, loan), Nigel Lonwijk (Wolves, loan). OUT: Ryan Law (Gillingham, loan). Photo: Pete Norton
15. Oxford United - 5/1
IN: Ciaron Brown (Cardiff, free), Stuart Findlay (Philadelphia Union, undisc), Yannick Wildschut (CSKA Sofia, undisc), Edward McGinty (Sligo, undisc), Josh Murphy (Cardiff, free). OUT: Luke McNally (Burnley, £1.8m), Mark Sykes (Bristol City, free), Ryan Williams (Perth Glory, undisc). Photo: Alex Burstow
16. Barnsley - 5/1
IN: Jamie Searle (Swansea, free), Luca Connell (Celtic, free), Robbie Cundy (Bristol City, free), Conor McCarthy (St Mirren, free), Nicky Cadden (Forest Green, free), James Norwood (Ipswich, free). OUT: Patrick Schmidt (Admira Wacker, free), Cauley Woodrow (Luton, undisc), Carlton Morris (Luton, undisc), Victor Adeboyejo (Burton, free), Jordan Green (Gillingham, free), George Miller (Doncaster, free), Callum Brittain (Blackburn, undisc). Photo: Dan Istitene