Manchester City earned their first point of the season in a match marred by a disgraceful challenge by Ben Thatcher on Portsmouth's Pedro Mendes.
Mendes needed treatment after being clattered by Ben Thatcher
Thatcher clattered into Mendes with his forearm at the start of the second half, sending the Portuguese midfielder skidding into the advertising boards.
It was the talking point of a turgid draw in which Joey Barton came closest for City with a sidefooted effort.
Portsmouth's Matthew Taylor forced a good save from Nicky Weaver.
But the limited goalmouth action was overshadowed by Thatcher's challenge which was at odds with a game which rarely flickered into life.
The home side were aiming to banish the memory of the 3-0 beating they took at Chelsea on the opening day of the season.
Portsmouth, meanwhile, wanted to keep the momentum gained by their hammering of Blackburn by the same score - but there was little danger of either side troubling the scorers during a dour match.
Pompey keeper David James was making a quick return to his former club and his first act was to watch Barton's side-footed effort go inches wide.
That was as close as either side got in the opening period.
Another Barton drive was saved comfortably by James, while Georgios Samaras sent a looping header on to the roof of the net.
Portsmouth threatened little and when Gary O'Neil did find some space in the box after Kanu's cross, he made a mess of his volley.
If the first half lacked excitement, Thatcher seemed intent on banishing any tameness with his savage challenge on Mendes at the start of the second period.
The City defender clattered into Mendes at full speed with his forearm raised, flattening the Portuguese midfielder and sending him flying off the pitch.
Mendes played no further part and was stretchered off after lengthy treatment, then taken to hospital.
Thatcher, for his part, was extremely fortunate to receive only a yellow card from referee Dermot Gallagher.
Portsmouth's sense of injustice was heightened 10 minutes later when City defender Micah Richards went unpunished after the ball apparently struck his arm in the box.
The visitors enjoyed more of the game after the break and City keeper Nicky Weaver produced a great save from Matthew Taylor after Pompey's best move of the match.
At the other end, substitute Ishmael Miller hammered in a shot which James parried but both sides appeared content to settle for a draw.
Stuart Pearce's conference featured an update on Sylvain Distin's possible move to Middlesbrough.
Harry Redknapp's post-match news conference was dominated by his thoughts on the Ben Thatcher challenge.
Man City: Weaver, Richards, Dunne, Distin, Thatcher, Sinclair, Barton, Reyna (Ireland 66), Samaras (Miller 71), Vassell, Dickov.
Subs Not Used: Hart, Dabo, Danny Mills.
Booked: Sinclair, Thatcher.
Portsmouth: James, Johnson, Primus, Campbell, Stefanovic, Taylor, O'Neil, Davis, Pedro Mendes (Hughes 52), Kanu, Mwaruwari (Todorov 65).
Subs Not Used: Jordan, Thompson, Pamarot.
Ref: D Gallagher (Oxfordshire).