A maiden First Grade century for a popular birthday boy and a rise up the all-time batting charts by a veteran who continues to defy age headlined the first day of round eight action in McDonald's Men's Premier Cricket on Saturday.

Playing in just his second top grade game on his 21st birthday, Manly-Warringah's Isaiah Vumbaca made a breakthrough hundred to help resuscitate his side's innings against Campbelltown-Camden at Raby Oval.

But it almost didn’t happen.

Vumbaca was on 99 when No.10 Ryan Hadley was run out after backing up too far.

With the last man now in and three balls remaining in the day's play, Izzy smashed the next ball to the fence to chalk up triple figures, triggering wild scenes among teammates.

The visitors had been 4-136 before Vumbaca (103) – with great support from Elliott Herd (60) - helped them reach 298.

UTS North Sydney's Rob Aitken celebrated his 21st birthday many, many years ago – 24 to be exact – but is still going strong for UTS North Sydney.

The veteran all-rounder made 58 against Gordon to take him to 11274 runs and past Phil Marks (11250) into 11th on the list of all-time First Grade run-scorers.

With keeper-batsman Aiden Bariol continuing his good form with the bat, scoring 116, the Bears made 340 at Chatswood Oval.

Blacktown Mounties have been doing it tough all season but their campaign may have turned a corner on the back of a breakthrough century to opener Toby Flynn-Duncombe against Hawkesbury.

After eight half-centuries and a previous top score of 72, Flynn-Duncombe batted all day in making an undefeated 136, hitting nine fours and three sixes.

Teammate James Newtown chipped in with a vital 83 as the Mounties finished 3-316 at Joe McAleer Reserve.     

St George's Evasio MacMillan finished with the day's best bowling figures – 4-26 - as Bankstown was rolled for a modest 220.

Skipper Nick Stapleton chipped in with three vital wickets and is seven not out after the Dragons lost an early wicket to be 1-11 in reply.

Incredibly, there were two hit wicket dismissals on the same day.

Sydney University opener Charlie Dummer was on 88 and closing in on his first top grade century when he slipped attempting a push through cover, crashing into the stumps.

And Sutherland's Chris Williams was out in similar circumstances after making his way to 33 against UNSW. 

Full scores here