Watson and Haddin notch up an Australian first-wicket World Cup record stand of 183 but not before the pacemen took some initial beating.
Australia thrash Canada to top group but still have reason to worry
Shane Watson (94) and Brad Haddin (88) shared an Australian first-wicket World Cup record stand of 183 before the title-holders, already through to the quarter-finals, finished on 212 for three in reply to Canada's 211 all out.
Haddin, given a life on 37 when Canada captain Ashish Bagai fumbled a possible stumping chance, was caught by Bagai off 40-year-old off-spinner John Davison, playing his final match before international retirement. In all he faced 84 balls with two sixes and 11 fours.
And 183 for one became 185 for two when Watson, who hit the tournament's biggest six at 104 metres during his innings, holed out off Harvir Baidwan.
Watson, reprieved on two when Rizwan Cheema failed to hold a swirling chance off paceman Baidwan, struck four sixes and nine fours in his 90-ball innings.
The openers' stand surpassed Australia's previous first-wicket World Cup best of 182 set by Rick McCosker and Alan Turner against Sri Lanka during the inaugural 1975 edition.
Ricky Ponting fell for just seven, miscuing a hook off fast bowler Henry Osinde to Davison.
The match ended with more than 15 overs to spare when Osinde bowled only the second wide of the innings.
Earlier, Hiral Patel, a 19-year-old India-born opener, took the attack to Australia's quicks with a career-best 54 after Bagai won the toss.
Canada, who have completed their World Cup campaign with one win and five defeats, were well-placed at 150 for two.
But Australia, now unbeaten in 34 matches at the World Cup since 1999, then took five wickets for 19 runs. Brett Lee ended with figures of four for 46.
The way Canada set about Australia's pacemen would have concerned Ponting ahead of the champions' final group match, against Pakistan in Colombo on Saturday.
Ponting angrily threw the ball to the ground after catching Baidwan when, despite his repeated calls, Steven Smith collided with his captain.
Canada promoted Davison to opener but he fell for 14 when caught behind off a clever slow bouncer from fast bowler Lee.
Patel though took Canada, whose only win at this World Cup came against fellow associates Kenya, to the fastest fifty of any team this tournament — in 29 balls — when he miscued a six off Mitchell Johnson over third man.
But Patel, whose highest score in 13 previous one-day internationals was 43, made no mistake in hooking a bouncer from Lee for six.
Patel completed his fifty in just 37 balls, with three sixes and five fours.
However, his blistering innings ended when he slashed medium-pacer Watson to Johnson at third man, leaving Canada 82-2 in the 12th over.
Zubin Surkari and Bagai kept Australia at bay with a stand of 68 until the captain, on 39, edged a cut off Tait to Haddin.
H Patel c Johnson b Watson 54
J Davison c Haddin b Lee 14
Z Surkari b Tait 34
A Bagai c Haddin b Tait 39
J Hansra c Lee b Krejza 3
R Cheema b Lee 2
N Kumar c Tait b Johnson 7
K Whatham b Lee 18
H Baidwan c Ponting b Krejza 17
B Rao b Lee 5
H Osinde not out 2
Extras (lb4, w11, nb1) 16
Total (all out, 45.4 overs) 211
Fall of wickets: 1-41 (Davison), 2-82 (Patel), 3-150 (Bagai), 4-157 (Hansra), 5-157 (Surkari), 6-161 (Cheema), 7-169 (Kumar), 8-195 (Baidwan), 9-204 (Rao), 10-211 (Whatham)
Bowling: Tait 8-1-34-2 (1nb, 4w); Lee 8.4-0-46-4 (2w); Johnson 10-0-43-1 (3w); Watson 6-0-22-1; Krejza 10-0-44-2 (2w); Smith 3-0-18-0
S Watson c Osinde b Baidwan 94
B Haddin c Bagai b Watson 88
R Ponting c Davison b Osinde 7
M Clarke not out 16
C White not out 4
Extras (lb1, w2) 3
Total (3 wkts, 34.5 overs) 212
Did not bat: M Hussey, S Smith, M Johnson, B Lee, J Krejza, S Tait
Fall of wickets: 1-183 (Haddin), 2-185 (Watson), 3-207 (Ponting)
Bowling: Osinde 9.5-0-53-1 (2w); Baidwan 10-1-41-1; Rao 7-0-46-0; Cheema 3-0-23-0; Davison 4-0-29-1; Patel 1-0-19-0
Result: Australia won by seven wickets