The towering striker, formerly of Colchester, enjoyed a successful return to Essex as he secured a 1-0 win with the only goal of the game in the 64th minute.
"This is a very satisfying win for us because we managed the game very well and the lads did everything I asked for," Laws said.
"Southend were really pressing quickly in the first half and we were giving the ball away too cheaply and that put us under pressure which we didn't need.
"The second half was a lot better after we had some words at half-time about keeping hold of the ball and that's what we did.
"I thought Sean McAllister was outstanding in midfield but the whole team was excellent and we managed it very well.
"The team is progressing well and if this is a sign of what is to come then it's all very positive."
Southend, who have now lost four games in a row, had the better of the first half, Ryan Leonard missing their best chance when he headed Kevan Hurst's right-wing cross straight at goalkeeper Sam Slocombe.
Michael Timlin, Freddy Eastwood and Hurst also went close from long range for the Shrimpers.
But Scunthorpe improved after the break and grabbed the only goal of the game when Southend left-back Ben Coker misdirected a defensive header into the path of Iwelumo, who nodded home from close range.
The Iron remained on top after going in front and could have doubled their lead late on when McAllister had a long-range shot impressively saved by Southend goalkeeper Daniel Bentley.