The Glen Innes product plucked an intercept to score his 14^th try and the Waratahs only in a disappointing performance.

With the Rebels looking to unleash Marika Koroibete down the short side, Newsome, who has earned a reputation as a bit of an intercept king, jammed in in defence and picked off the pass, and raced away 25 metres to put the Waratahs up 7-3 after seven minutes.

It would be the only time they would be in front in the match though as the Rebels dominated possession and territory.

As Newsome, who assumed the captaincy when Rob Simmons was forced to leave the field in the second half with what was later revealed to be broken ribs, acknowledged to Fox Sports' Rod Kafer post-match the Rebels got the jump on them physically.

Illdiscipline was also a big issue. The Waratahs conceded 17 penalties and twice had a player in the bin, and gifted the Rebels 15 points.

"It's been a bit of an issue for us this competition and it snuck in today," Newsome said.

They did have some patches of momentum in the first half, but after trailing 19-10 at the break couldn't get into the game in the second half.

"I feel like whenever we have good continuity of our ball we look like we're going to make yards but some errors crept in there and we just weren't able to have that continuity throughout the whole game," he said.

Newsome tried hard, and as well as the try also came up with some big plays in defence - late in the first half he made a try-saving tackle on Reece Hodge. But his night didn't end on the best note, being steamrolled by Koroibete late in the game.

The Waratahs have the bye and, asked by Kafer what areas the Waratahs need to work on ahead of the second half of the competition, Newsome replied "a bit of everything".

"Our game management is a work in progress each week but I think that focus and concentration to not give those other teams entries into our area through simple errors..." he said.