Jermain Defoe doubled the lead from the penalty spot and we looked in control until Kanu headed home to make it 2-1 just before the interval.
Portsmouth came more into the game in the second half without seriously testing Paul Robinson until added time when England's number one superbly tipped over Lumana Lua Lua's header. At the other end, James had to be at his best to keep out efforts from Jermaine Jenas and Defoe.
"If you see the chances we had over the whole game, we deserved to win," said Martin. "I felt in the first half we played some good stuff.
"Portsmouth were up for it and I knew we were in for a tough game and in the first half we handled it well.
"In the second half we had some tired legs out there. We had to sit back and that's never an intention, but sometimes you have to.
"They had their goal and Paul Robinson's amazing save from Lua Lua at the end, so that's one goal and one chance. Overall, we had some great performances - Didier Zokora, Jermaine Jenas, Michael Dawson at the back. I'm only pleased with the performances of our lads."
Martin Jol felt we deserved to bag maximum points following our first half display against Portsmouth on Sunday.Danny Murphy gave us the perfect start with the opening goal inside the first minute at the Lane, following in to finish from close range after David James parried Dimitar Berbatov's header.