Goals from Marcus Harness, Lee Brown and a John Marquis double condemned the Black Cats to a 4-0 defeat – their worst since suffering the same scoreline in January 2018 under former boss Chris Coleman against Cardiff City.
Despite the treacherous conditions, Pompey were able to adjust and inflict a damaging defeat to the Wearsiders as they were replaced at the top of the League One table.
And without a league fixture this weekend due to the international break, Johnson and his side must sit and reflect on their humiliating defeat on the south coast until they return to action with a trip to Gillingham on Saturday week.
Following Saturday’s wake-up call, we look at all the League One transfer, contract and injury news.
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1. Sheffield Wednesday to tie down defender
Sheffield Wednesday are close to tying up a new deal for defender Liam Palmer as per reports from the Sun on Sunday. Palmer is a key part of Darren Moore’s side and has been a mainstay in the Owls’ backline so far this season and now looks set to extend his stay at Hillsborough before his current deal expires at the end of the season. (Photo by George Wood/Getty Images) Photo: George Wood
2. Portsmouth's Harness upbeat after win
It was a bad day at the office for Sunderland as the Black Cats suffered a heavy defeat against League One rivals Portsmouth at Fratton Park and Marcus Harness, who grabbed the Pompey opener, has told Hampshire Live the result was about showing their League One promotion credentials. “We wanted to show how good a team we are and to play more like that than we did at Burton," said Harness. “It’s about focusing on the next game and making sure that we perform at a consistently high level to set us up for the rest of the season. We could have scored four or five goals on other occasions, so it’s nice to beat someone heavily and keep a clean sheet." (Photo by Mike Hewitt/Getty Images) Photo: Mike Hewitt
3. Ex-Chelsea defender Sinclair joins Rovers staff
Frank Sinclair has joined the coaching staff at Doncaster Rovers. The former Chelsea and Leicester City defender played over 180 games in the top flight and has since had spells with Colwyn Bay, Brackley and Hednesford in management. The 49-year-old adds to Richie Wellens’ backroom staff at the Keepmoat Stadium as they look to build on just a second win of the season on Saturday.. \ Mandatory Credit: Shaun Botterill /Allsport Photo: Shaun Botterill
4. 'We should have won at Sunderland' - says Bolton defender
Bolton Wanderers defender Ricardo Santos believes his side should have beaten Sunderland in their recent meeting at the Stadium of Light. Ian Evatt’s side pushed the Black Cats to their limit as Johnson’s side edged out Wanderers by a single goal. And the Bolton defender believes his side can continue to climb the table. “We are happy with where we are at the moment but we should have probably won at Sunderland,” Santos told the Manchester Evening News. "All our performances have been good recently, we just need to keep adding goals and rolling teams over. I think if we gave it a real go we would climb higher up the table.” (Photo by Jacques Feeney/Getty Images) Photo: Jacques Feeney