South Africa [Images] skipper Graeme Smith [Images] ended his prolonged slump in form with a strong all-round performance to lead his team to a five-wicket win over Sri Lanka [Images] in a one-day international at the WACA in Perth on Tuesday.

Smith took career-best figures of three wickets for 30 runs as Sri Lanka collapsed to be all out for 221 then made 41 to lay the foundations for a comfortable South African victory.

"It was a good win for us at the end of the day," Smith said in a televised interview. "It gives us a bit of confidence going into the next game against Australia [Images]."

South Africa's victory means Australia are already assured of a place in the best-of-three finals series.

South Africa need to win just one of their last three matches to claim the other spot ahead of Sri Lanka.

Sanath Jayasuriya [Images] top-scored for Sri Lanka with a brilliant 86 from only 65 balls but did not get enough support from the lower order.

South Africa cruised to the victory target with 4.5 overs to spare. In-form opener Boeta Dippenaar held the innings together with 87 from 94 deliveries, decorated by seven fours and three sixes.

Jayasuriya smacked nine boundaries and three sixes in a dazzling display but only Dilshan Tillekeratne (37) and Jehan Mubarak (31) made more than 20.

Smith, a part-time spinner, dismissed Mubarak, Jayasuriya and Mahela Jayawardene [Images] in a four-over spell to trigger a collapse that saw Sri Lanka's last nine wickets tumble for just 84 runs.

South Africa were always in control after Smith and Dippenaar piled on 84 in 16 overs for the opening wicket.

There was a slight wobble in the middle-order when Sri Lanka spinner Muttiah Muralitharan [Images] grabbed three wickets but an unbeaten 30 from Mark Boucher [Images] and 20 not out from Ashwell Prince [Images] steered the South Africans home.

Scorecard:

Sri Lanka Innings
 J. Mubarak b Smith 31
 S. Jayasuriya c Prince b Smith 86
 K. Sangakkara c Kemp b Langeveldt 16
 M. Jayawardene lbw b Smith 1
 M. Atapattu c Rudolph b van der Wath 7
 R. Arnold c Kemp b Pollock 15
 T. Dilshan run out 37
 C. Vaas run out 0
 N. Kulasekara [Images] c Kemp b Pollock 1
 M. Bandara run out 11
 M. Muralitharan not out 1
 Extras (lb-10 nb-2 w-3) 15
 Total (all out, 47.4 overs) 221

Fall of wickets: 1-94, 2-137, 3-142, 4-144, 5-159, 6-179, 7-179, 8-182, 9-216, 10-221

Bowling
 S. Pollock 10 - 3 - 17 - 2
 C. Langeveldt 10 - 0 - 50 - 1 (nb-2 w-1)
 A. Hall 9 - 0 - 48 - 0
 J. van der Wath 8.4 - 0 - 66 - 1
 G. Smith 10 - 0 - 30 - 3 (w-2)

South Africa Innings
 G. Smith c Sangakkara b Muralitharan 41
 B. Dippenaar c Sangakkara b Muralitharan 87
 J. Rudolph st Sangakkara b Bandara 25
 H. Gibbs b Muralitharan 4
 M. Boucher not out 30
 J. Kemp st Sangakkara b Bandara 6
 A. Prince not out 20
 Extras (b-4 nb-1 w-6) 11
 Total (for 5 wickets, 45.1 overs) 224

Fall of wickets: 1-84, 2-164, 3-164, 4-175, 5-190

 Did not bat: S. Pollock, J. van der Wath, A. Hall, J. Botha

 Bowling
 C. Vaas 9 - 1 - 39 - 0 (w-3)
 R. Arnold 1 - 0 - 11 - 0
 N. Kulasekara 5.1 - 0 - 22 - 0
 M. Muralitharan 10 - 0 - 44 - 3 (nb-1 w-2)
 T. Dilshan 7 - 0 - 44 - 0
 M. Bandara 10 - 0 - 47 - 2
 S. Jayasuriya 3 - 0 - 13 - 0 (w-1)

Result: South Africa won by 5 wickets