One win in five league games since the turn of the year had seen the Welsh region slip off top spot and out of the play-off places.
And with Munster - who began the weekend top of the pile - visiting the Liberty Stadium on Saturday, Tandy's men faced another tough test.
However, 21 points from the boot of Sam Davies and a Dan Baker try helped Ospreys to a 26-12 triumph and the boss is hoping to see them kick on with just five regular-season games left.
"I feel as if we have a semblance of control now," said Tandy.
"If we had not picked up a result against Munster we would have been really chasing and would have had to win our last five games with bonus points.
"We could have become a bit detached from the likes of Munster and Glasgow, but now we are back in the pack.
"We really didn't want to be chasing down too many points. It's still going to be a big ask and there will be some ups and downs along the way. My guess is it will go down to the wire."
Davies took the headlines on the day after playing a key part in Baker's try, converting it and adding six penalties to keep Munster at bay, while Tyler Ardron's all-action display earned him the man-of-the-match award.
Late tries from Donnacha Ryan and Keith Earls saw the visitors threaten to pinch a bonus point but they eventually ran out of time.
"I was proud of the boys. The way they have gone about their week in training has been outstanding and that has been replicated on the playing field," added Tandy.
"We have grown over the last four weeks and we have said all along we were going to have ups and downs in this group but the experience of losing can be a positive."
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