The Las Vegas Blackjacks have caused one of the biggest upsets in years in the Southern California championship with a stunning 21-6 win over OMBAC in the first round of the playoffs.

Vegas, playing in Division One for the first time this year, hosted the San Diego club and outscored their opponents three tries to none. The Blackjacks crossed for one try in the first half and two more in the second period to secure their place in the semi-finals.

The first twenty minutes of the game saw both teams trade penalty goals. The Blackjacks got on the board first when flyhalf Dallas Orchard kicked a penalty to put his side up 3-0. OMBAC answered with a three-pointer of their own to level the scores, before Orchard edged his team in front with his second conversion.

In the second quarter of the match, Blackjacks hooker Mitch Brown, formerly with Sydney club Norths, scored an unconverted try to put Vegas further ahead 11-3. OMBAC closed to within 11-6 with their second successful penalty goal and that's how the first half ended.

In the second half, the Las Vegas forwards dominated the opposing pack, due largely to the go-forward marshaling by scrumhalf and coach Anthony Hunter. Prop Glen Amador posted the next score for the Blackjacks when he crashed over the line for an unconverted try to put the homeside up 16-6.

That was followed by the final score of the game when Vegas winger Roger Cowan, reputedly one of the quickest players in the Southern Cal competition, raced in for the Blackjacks' third try. Again it went unconverted, but it didn't matter as Las Vegas had the game in its keeping at 21-6.

Fijian-born lock Sidney Drodrolagi was voted man-of-the-match for his tireless efforts, particularly in the lineouts where he secured a glut of possession. Also among the standouts for Vegas was captain Hank Greenburg.

"Our forwards were all over them," said Blackjacks flyhalf Dallas Orchard. "The ball hardly got out to the backs all day. Our defense was great, even though OMBAC had a much bigger team than ours. We're really happy, this is probably the biggest win in the club's history."

The other first round playoff game pitted Belmont Shore against the Huntington Beach Unicorns and it was Shore that triumphed 28-3.

In what was at times a scrappy game, Shore went to the main break with a narrow 7-3 cushion. The undefeated Belmont side then went to town in the second stanza and booked a spot in next weekend's semi-finals.

The top seeded Santa Monica Dolphins and Back Bay Sharks enjoyed the week off, by virtue of being the higher seeds, and will host Belmont Shore and Las Vegas respectively next week.