Stepping cleanly from box one, the daughter of Collide and Winsome Bluebird stuck to the rail as Majestic Gem (box five) exploded from the traps to assume the early lead. Swinging for home and the blue bitch hooked to the outside of the leader and dashed to the lead in the run to the line to score by 1.5 lengths
Golden Gossip (box two) railed beautifully in the home straight to snare second for Christine Robartson ahead of a tiring Majestic Gem in third position.
The race favourite, Astrophysic, was never out of trouble from box four, thundering home down the centre of the track to narrowly miss a placing, finishing fourth.
The winner clocked a quick 22.56, just over a length off her 22.45 personal best over the track and distance.
Sialia, a half-sister to champion bitch Miata, has now won 12 races from 23 career outings with more than $45,000 in prizemoney earnings. The lightly raced bitch, which turns three next month, looks to have plenty of racing and success left in her.
Group Three Mandurah Mail Birthday Cup full results
1st: Sialia (1) – Paul Stuart
2nd: Golden Gossip (2) – Christine Robartson
3rd: Majestic Gem (5) – Greg Martin
4th: Astrophysic (4) – Paul Stuart
5th: Powerhouse (3) – Andrew McLaren
6th: Last Day (7) – Christine Robartson
7th: Fun Princess (6) – Lexia Isaac
8th: Walkaway Ablaze (8) – Emily Frazer
1st split: 6.55
2nd split: 11.83
Run home: 10.73
Margins: 1 1/2 L x 1 1/4 L