The upset was Clarence's only three points from a NPL Tasmania match since 2017 following two draws last year.

Lachlan Burt struck the winner for the hosts from the spot in the 64th minute.

Jono O'Neill was handed a yellow card from the penalty for clipping the heels of Burt.

Riverside Olympic coach Alex Gaetani was finding the defeat hard to swallow than any of the side's first seven games in a new competition.

"It was very disappointing to lose today," Gaetani said.

"I think any loss there is an element of disappointment, but it was a game that we needed to win to an extent.

"Certainly in terms of general play and chances, it was one-sided in our favour.

"We had issues finishing those chances and they won a penalty at the other end.

"It was hugely disappointing in that respect alone."

That ascendancy at Wentworth Park came to nothing.

Clarence conceded nine, eight, five, 13, nine, nine and six goals so far in the league, but Gaetani's men failed to add any to the sizeable tally.

A frustrated Roos had 16 shots to their rivals' five of which eight were on target compared to three.

"There was a certain level of anxiety when your chances don't go the way they should go," Gaetani said.

"The longer that goes on the more nervous we got.

"I probably think we were nervous to begin with.

"It was a game we were expected to win and a position we've never been in before."

Launceston City appeared to redeem its poor Lakoseljac Cup exit two days earlier in a 0-0 draw at Kingborough.

The scoreless result pushes City up one place into sixth past the Lions on goal difference amid a crowded bottom four that also includes both Riverside and Clarence.

This was after City coach Lino Sciulli was forced to make changes to a depleted squad after Saturday.

"I was very happy with how the boys played with all things considered," he said.

"Injuries and that don't concern me; you play who you have when you have to.

"You put your 11 players on the paddock and see how it pans out."

RELATED: Launceston City bow out of the Lakoseljac Cup while new NPL Tasmania side Riverside advance

Lachlan Clark pulled off a number of top saves to keep a clean sheet for the visitors.

Sciulli felt the keeper's resilience was indicative of the players making a stand.

"I was happy with that because if we had played like what we did on Saturday, we would have our tail between our legs again," he said.

"Fortunately they showed a lot from their response as it hurt a little bit."

Devonport City dropped its first points, the Strikers losing 2-1 to Hobart Zebras.