Lyndon Dykes scored the only goal of the game in the 14th minute as Scotland revived their World Cup qualifying hopes, climbing to third place in Group F ahead of Tuesday night’s vital clash with Austria in Vienna.
"We didn't concede and we scored from one of our chances, that's clinical enough,” said Clarke.
“We will try and build on what we did tonight. If you are not creating chances, you are more worried than if you are creating chances and not scoring.
"It was important to play on the front foot and get a clean sheet and I think we did that. It was a good night for us.
"Tuesday's irrelevant, my team selection was with tonight in mind. We had to win otherwise Tuesday would have been a dead rubber. It was nice to get the three points and we look forward to a trip to Vienna and a tough game against Austria.
"You always need the second goal to stop that nervy five minutes at the end where everyone in the stadium gets a little too nervous but we saw the game out well and I made some changes to make sure we did that.
“We spoke at half-time about making sure it was 'Moldova nil' and that's what we did. If you keep clean sheets, you win games.
"With a little more composure, the scoreline would look better but one-nil is enough to get you three points.”
Clarke was able to enthuse about the performances of 20-year-old midfielder Billy Gilmour, who excelled once more, and 19-year-old right-back Nathan Patterson who shone in his first starting appearance for Scotland and played a crucial role in Dykes’ goal.
"Nathan played a really good game but I wasn't surprised because he's played well for Rangers,” said Clarke.
“When I put him in the team, I knew what he would give us. He has good energy going forward and almost got his goal on his first start for his country and fortunately Dykesy was there to knock it over the line.
“Nathan gives you quality, good on the ball. Second half he tired a little but he showed a good maturity to sit and play his position. He can do both sides of the game. He will be a big player for us going forward and a big player for us now.
“Billy tired a little bit second half but it was important to get Billy on the ball, he dictates the tempo and makes us pass and play. Two good young ones but don't forget the senior ones as well.”
Clarke will assess a number of bumps and bruises among his squad before they travel to Austria and has criticised the scheduling of the World Cup qualifiers as Scotland prepare for a third game in seven days.
"There are about seven or eight knocks, I won't go through them all – there's too many,” said Clarke. “It's a tight schedule, a poor schedule to be honest."