Darren Ferguson felt his side could have made victory at Pompey more comfortable.
Doncaster ran out 2-1 winners at Fratton Park on Saturday with two first-half goals.
Ferguson explained his side set out to press the Blues high up the pitch and start quickly.
They were holding on at the end, however, and the Scot felt that could have been avoided.
Ferguson told thornegazette.co.uk: ‘First of all it was a good result, that’s the most important thing.
‘I was pleased with the start to the game as well.
‘We spoke about the fact we wanted to set our stall out.
‘We wanted to press and try to dominate the opening part of the game. We were very comfortable.
‘I was just disappointed we couldn’t go in with a two-goal advantage.
‘The good thing for me is that we knew they’d have periods of the game where they were dominant.
‘We felt that we would have as well but we needed to make sure when we were that we scored – and we did that.
‘We knew we’d be up against a strong team. I think that’s their first home defeat.
‘Again, we could have made it a lot more comfortable than how it ended up, just by our decision making.
‘The two strikers both got a goal and it’s a fantastic win.’
Doncaster have now followed up a defeat at Luton and draw with Carlisle by beating Pompey.
That sees Ferguson’s side now second in the table behind leaders Plymouth.
Ferguson said: ‘It’s been a tough week for us, a hard week which we knew it would be but we’ve finished it off with three points a good win.
‘We were all disappointed at Luton because given the initial third of it, we should have been out of sight. It was disappointing to lose.
‘On Tuesday we felt like we let Carlisle off a little bit, missing the penalty.
‘We rode our luck a bit at times but we deserved a bit of luck. We’ve been due it.’
– JORDAN CROSS