LIVERPOOL - Ayegbeni Yakubu took his goal tally for the season to 18 with two against his former club, making sure Everton reclaimed fourth spot in the Barclays Premier League.
Liverpool, winners earlier in the day at Bolton, had taken fourth place - but their hold on it did not last long.
Everton rose to the challenge instantly and took the lead inside a minute through Yakubu - only for Jermain Defoe to equalise in the 38th minute.
Pompey appeared capable of snatching a point - but the Toffees raised their game and Tim Cahill headed his 10th goal of the season before Yakubu blasted his 18th in a rousing climax.
Joseph Yobo and Steven Pienaar overcame stomach bugs to hold their places in Everton's side, but midfielder Mikel Arteta did not even make the bench because of his persistent groin problem.
Everton fielded the side that won at Manchester City on Monday, while Portsmouth made one change from the side that beat Sunderland last time out - Kanu coming in up front for Milan Baros.
And Pompey were caught cold by their former player almost immediately.
The big Nigerian chased down Lassana Diarra from the kick-off, and was fouled by the French midfielder.
When Pienaar lifted the free-kick into the box, Yobo flicked it on and Yakubu was all on his own to head past David James from six yards.
His 17th goal of the season, timed at just 47 seconds, gave Everton the perfect start but spoiled the 61st birthday of Pompey boss Harry Redknapp.
England coach Fabio Capello, who had rushed from Bolton to Goodison Park to take up a seat in the directors' box minutes from kick-off, will have been heartened to see nine Englishmen start the game.
Everton did not fashion another opportunity until the 24th minute - some neat one-touch passing ended with Leon Osman shooting wide.
Sylvain Distin was booked in the 32nd minute for a foul on Cahill - and the visitors were largely ineffective up front at this stage.
Diarra was denied a free-kick following a challenge by Lee Carsley - and became involved in a heated exchange of views with the Everton man behind referee Andre Marriner's back. Diarra pushed Carsley, who kicked out but failed to connect.
However, the visitors were much happier soon after when they grabbed a 38th-minute equaliser.
Glen Johnson fired over a cross from the right and Defoe managed the faintest of touches in the six-yard box as the ball eluded Howard.
Pompey started the second period much sharper and faster, and in the 50th minute Kanu forced his way into the box, eluded Yobo and Joleon Lescott, before being denied by Howard's block.
But the spark soon slowly faded and the game became mundane again, bogged down in midfield.
Pienaar was booked for felling Papa Bouba Diop on 64 minutes, and soon after Everton attempted to inject some pace in the game by bringing on Andrew Johnson.
The striker replaced Tony Hibbert, with Phil Neville dropping to right-back to give Johnson the flank to attack.
But Everton's breakthrough, when it came, was from the left.
Yakubu had generally been kept quiet by Distin and Sol Campbell, but in the 73rd minute he kept possession well out on the left and fed Pienaar on the edge of the box.
The little South African then produced a neat chip for Tim Cahill, who had shaken off the attention of the Portsmouth defence, to head past James from close range.
The goal forced Redknapp to send on an extra striker in Ghana international John Utaka for midfielder Diop as Pompey went in search of parity again.
But in the 81st minute that plan was ruined by Yakubu, who made it 3-1 to the home side.
The Nigerian collected a long crossfield ball from Carsley, held off and neatly turned Campbell, before lashing a shot home.
He was substituted soon after, to a standing ovation, with Victor Anichebe coming on - Leighton Baines followed for Pienaar - as the home side saw out time.
