The Boomers lost 93-83 to Canada in a high-quality Olympic basketball battle that leaves Australia needing to fell Giannis Antetokounmpo’s Greece to ensure a quarter-final berth.

Australia played wonderfully in Lille on Tuesday to lead by four points at half-time, before Shai Gilgeous-Alexander, RJ Barrett (24 points, seven rebounds, five assists) and their NBA support cast overwhelmed them to seize control of their Olympics pool of death.

Gilgeous-Alexander was practically unstoppable for the World Cup bronze medallists, scoring 16 points in just 25 minutes on eight-of-10 shooting.

Josh Giddey had won the earlier exchanges (19 points, seven rebounds, six assists) before his former Oklahoma City teammate took control in the second half.

Tokyo bronze medallists Australia, who impressively beat Spain in their Games opener, will play the winless Greece on Friday.

Victory would likely see them finish second and earn a ticket to Paris’s quarter-finals, while a loss would likely leave them among a pack of teams hoping to be there as one of the two best-performed, third-placed teams.

Things began brilliantly as Australia shared the love in Lille on Tuesday, highly-efficient offence and swarming defence offsetting the brilliance of emerging NBA superstar Gilgeous-Alexander in the first half.

Patty Mills and Jack McVeigh hit crucial triples, Jock Landale (16 points, 12 rebounds) was clever around the rim, Dante Exum (15 points) impactful in his return from injury and Dyson Daniels was again a problem on defence as they led by five.

But Canada put the heat on Giddey and the Boomers began to leak turnovers, with more tough shots from Gilgeous-Alexander, Barrett and Lu Dort putting them up 10.

Exum’s return changed the mood though, the Dallas guard driving to the rim and sparking a comeback that, after two late McVeigh triples, had Australia down by two at the final break.

They couldn’t buy a bucket in a 21-13 fourth quarter, Gilgeous-Alexander icing the cake with a neat alley-oop pass to Dwight Powell for an 11-point lead with one minute to play.

Earlier, Spain kept their Games hopes alive with a 84-77 defeat of Greece, Santi Aldama the hero with 19 points and 12 rebounds.

Australia’s water polo Sharks have devoured the reigning Olympic and world champions Serbia in a Games sensation at the Paris Aquatics Centre.

Heavy underdogs, Tim Hamill’s side, who’d lost their first match to Spain and were in desperate need of a victory to get their tournament on track, came out firing on Tuesday to blitz the world’s leading side by the most unlikely 8-3 scoreline.

The Sharks’ standout was Luke Pavillard, who powered home four goals with his left-hand tracers, while Matt Byrnes chipped in with two. Jacob Mercep and Charlie Negus also got on the scoresheet.

The Serbs were left stunned, their coach going ballistic at poolside after watching the Australians race into a 6-1 halftime lead, thanks to a brilliant second period in which both Pavillard and Byrnes netted twice.

The Australians’ excellence was only matched by a curiously error-ridden effort from the champions, who had also struggled in their opening game before edging Japan by one in a 31-goal thriller.

Yet the side who hit 16 in that match found the suffocating Australian defence much more difficult to penetrate.

Star man Dusan Mandic, who had scored seven himself against Japan, was held to just two goals as the two-time defending champions were already six down by the time he notched his first just before half-time.

By then, the Australians were in dreamland with Pavillard, a 28-year-old from Kalgoorlie, having already notched his hat-trick with pin-point shooting. His fourth followed soon after the break, leaving Serbia 7-1 down going into the last period.

They rallied briefly, narrowing the deficit to four, before Negus delivered the coup de grace.

He unleashed an unstoppable shot from eight metres that deflected off the post and in, leaving the seeking Serbs to ponder a remarkable upset as they seek to emulate the modern Olympic record of Hungary (2000-2008) in winning three titles in a row.