A POTENTIAL season-ending knee injury to Matt Toomua added salt to the wounds of the defiant ACT Brumbies as they lost at home for the first time this year.

Despite fighting until the death, the Brumbies constant errors helped the Sharks hold on for a three-point win at Canberra Stadium last night.

The Brumbies' fighting spirit ensured the match was still up for grabs in the last minute when Nic White scored a try with just 30 seconds remaining. The Brumbies then launched one last attempt to steal victory and went almost the length of the field before their charge came to a halt when Ben Alexander dropped the ball well after the full-time siren.

But while the tight loss hurt, Toomua's knee injury was the knockout blow. The Brumbies' five-eighth dropped to the ground in agony in the 48th minute when he stepped off his left foot in attack.

He felt his knee buckle underneath him and went for scans last night to check the severity of the anterior cruciate ligament damage.

It was the first time the Sharks had won in Canberra since 1998 and their first away victory this season.

It was a scrappy opening to the match. The Brumbies tried to play field position, but fullback Jesse Mogg put the ball out on the full twice and they couldn't keep mistakes out of their play.

Former French international Frederic Michalak opened the scoring in the 13th minute with a penalty goal.

After the Brumbies levelled, Michalak then threw a cut-out pass to fullback Riaan Viljoen who scored in the corner.

Mogg erased his earlier errors 12 minutes before half-time when he made a scintillating break down the right wing. Christian Lealiifano sent the ball wide and Mogg sprinted away. When the defenders closed in, he chipped over the top and regathered to score the Brumbies' first try.

The Sharks stole the lead back when Toomua's pass was intercepted by Odwa Ndungane and he found Viljoen who scored his second five-pointer.

Another Brumbies mistake handed the Sharks their third try.

Henry Speight failed to clean up a loose ball 5m out from his own line and Willem Alberts dived over to give the Sharks a 22-16 lead.

The Brumbies couldn't get any momentum in the second half because of their constant errors.

The Sharks sealed the win with a 99m turnover try. Trailing 19-22, the Brumbies were pushing for the lead and had the ball for 16 phases before the Sharks stole the ball.

They streaked away down the left side with winger Lwazi Mvovo dashing the last 22m to give his team a 10-point lead.

The Brumbies had plenty of chances to get back in the match, but they couldn't control the ball.

Debutant front-rower Scott Sio got over the line but dropped the ball reaching out for the try.

They then had their last chance at victory and held the ball for 14 phases before they dropped the ball.

The Brumbies will play defending champions the Queensland Reds in Brisbane next week.

SHARKS 29 (Riaan Viljoen 2, Willem Alberts, Lwazi Mvovo tries Frederic Michalak 3 cons pen) bt BRUMBIES 26 (Jesse Mogg, Nic White tries Christian Lealiifano 2 cons 4 pens) at Canberra Stadium. Referee: Keith Brown.