The bubble of expectation surrounding the Chiefs was quickly burst when they lost their opening Super 14 rugby match of the season 21-15 to the Brumbies tonight.

The Brumbies were well worth their success at Waikato Stadium in Hamilton as the Chiefs were reminded of the competition's harsh realities.

Chiefs supporters and even some from outside the franchise's boundaries view the team as genuine title contenders this season, a huge show of faith given their record of under-achievement at this level.

Their campaign began poorly tonight when they showed their usual competitiveness without ever threatening to derail a polished Brumbies outfit.

The Brumbies dominated the early exchanges and led 10-0 after just 12 minutes, with all the points coming courtesy of Wallabies centre Stirling Mortlock.

The veteran scored a try after just five minutes when the Chiefs defence was found wanting on the short side.

Mortlock added the extras, then landed a penalty as the Brumbies, traditionally Australia's best team, threatened to turn the match into a one-sided contest.

However, the Chiefs showed glimpses of why their supporters think this could be their year by rebounding from the early setbacks despite losing captain and lock Jono Gibbes for 10 minutes.

Gibbes was sent to spend time in the sinbin for a high tackle on wing Mark Gerrard in the 15th minute although his team did well to limit the damage caused by his absence.

Gibbes watched on as wing Sosene Anesi put in a determined run down the right flank, beating three defenders on his way to the tryline.

It remained 10-5 at the halftime break, by which stage South African referee Mark Lawrence found cause to sinbin another two players -- the home side's Marty Holah and his opposing flanker George Smith.

The decisive period came early in the second spell when the Brumbies cleared out to an 18-5 advantage.

With their forwards lifting in intensity, the visitors created space for winger Clyde Rathbone to have an unimpeded run to the tryline down the right-hand touchline then first five-eighth Julian Huxley landed a 53m penalty.

Huxley inexplicably missed a gift three-pointer from a handy position in the 61st minute before the Chiefs were given an unexpected lifeline when Anesi stole an intercept and scampered 70m for a fortuitous try four minutes later.

There was nothing lucky about their next try, when replacement wing Lelia Masaga slipped through Huxley's tackle near touch to score in the 74th minute as the Chiefs suddenly threatened to steal victory with the difference now sliced to three points.

Stephen Donald missed the wide-angled conversion attempt to give him a none-from-four goalkicking return before Huxley completed the scoring with an easy penalty.

Result of a Super 14 rugby match at Waikato Stadium in Hamilton tonight:-

Brumbies 21 (Stirling Mortlock, Clyde Rathbone tries; Julian Huxley 2 pen, Mortlock pen, con) Chiefs 15 (Sosene Anesi 2, Lelia Masaga tries). Halftime: 10-5.