An eight-run win barely hinted at the full story as James Curran, Ben Humphrey and Chathura Athukorala all recorded centuries.

Launceston's 6-348 surpassed Riverside's 7-321 dating back to 2000-01 as the highest one-day score against Westbury in the Shamrocks' NTCA history.

However, the visitors' reply of 8-340 was their second highest score, one short of the 4-341 against George Town in 2012-13.

The club was also trawling its record books to confirm that ACL recruit Athukorala's knock of 163 was its highest one-day innings for 32 years.

In a hugely entertaining contest, the unbeaten Lions were teetering at 4-43 before a mammoth 251-run partnership changed everything.

Humphrey (132) and Curran (116) ripped into the attack, claiming 13 fours each and seven maximums between them in a devastating display of big hitting.

The pair shared deserved hugs as they both passed three figures.

Daniel Smith also chipped in with a helpful late 36 off 15, finding the boundary every third ball, to set up a huge total.

Nick Spencer topped the bowling stats with 3-60 off his 10 overs.

Undaunted on the back of three straight wins, Westbury began the chase with the top three all falling in the 20s before Athukorala upped the ante.

His 163 came off exactly 100 deliveries and featured 18 fours and eight sixes.

Three more teammates passed 20 but the chase fell agonisingly short as Humphrey completed a superb day with 3-59 and Dihan Cloete took 3-49 including the priceless wicket of Athukorala.

South Launceston kept Mowbray winless with a comfortable five-wicket win at Invermay Park.

Inspired by his player-of-the-week performance in round six, Spencer Hayes provided the backbone of the Eagles' total of 6-204.

Hayes hit 53 off 37 balls to record back-to-back half-centuries before being undone by the wily spin of Jeremy Jackson who claimed the day's best bowling figures of 3-21 off just five, which included a maiden.

Luke Scott (41), Will Dakin (40) and Jason Snare (37) also dug in at the top of the order.

Led by Ben Spinks (2-39) and James Storay (2-34), the Eagles bowlers took regular wickets but it was never going to be enough to halt the South juggernaut.

A couple of days after captain Sean Harris issued a warning about his side relying too heavily on the batting of Nathan Philip, it was a familiar name anchoring the chase.

But Philip (53 not out off 42) had been well set up by Harris (55) and Martin Potsekayi (31) as three other batters made the teens.

Jackson was welcomed to the crease to watch the winning run hit with 8.5 overs to spare.

Riverside had the bye.

Up on the Coast, Wynyard won a round seven thriller at Latrobe by one wicket.

The hosts were all out for 174 in the 48^th over and the Tigers were nine wickets down when the winning run was hit with just four deliveries left.