SYDNEY (Agencies) David Warner scorched the second fastest international half century in Twenty20s short history as Australia completed their unbeaten summer with a bang at the SCG on Tuesday night. In reply to the West Indies 7-138, the home side reached the target with eight wickets and 50 balls to spare. Warner (67 off 29 balls with seven sixes) and Shane Watson (62no off 33 balls) caned the touring sides attack. Indias Yuvraj Singh holds the record for the fastest Twenty20 half century from 12 balls against England in South Africa in 2007. That mark was in danger with Warner on 22 off four balls at one stage before eventually reaching his fifty off 18 balls, the fastest effort on Australian soil and by an Australian. There was some drama in Warners innings with the left-hander warned by the umpire for taking strike as a right hander as spinner Narsingh Deonarine came in to bowl. But it meant little to the crowd who enjoyed the carnage that started with Warner taking 22 off the opening over of the innings by paceman Kemar Roach. Warner was not quite as potent against the spinners but still punched Deonarine over point to bring up his fifty before falling at the hands of Nikita Miller in the deep. SCOREBOARD WEST INDIES innings (20 overs maximum) CH Gayle c Smith b Harris 12 Dowlin c Smith b Christian 31 Morton c White b Harris 0 KA Pollard b Watson 5 Hinds run out (White/Smith) 0 Smith c Warner b Christian 8 N Deonarine not out 36 Ramdin c Warner b Tait 9 DJG Sammy not out 26 EXTRAS: (lb 5, w 6) 11 TOTAL: (7 wickets; 20 overs) 138 Fall of wickets: 1-26, 2-27, 3-50, 4-51, 5-63, 6-77, 7-98 BOWLING SW Tait 4-0-27-1-6.75(3w) RJ Harris 4-0-27-2-6.75(1w) MG Johnson 4-0-22-0-5.50(1w) SR Watson 3-0-15-1-5.00 Christian 4-0-29-2-7.25 SPD Smith 1-0-13-0-13.00 AUSTRALIA innings (target: 139 runs from 20 overs) SR Watson not out 62 Warner c Pollard b Miller 67 Haddin c Morton b Miller 6 DT Christian not out 4 EXTRAS: (w 3) 3 TOTAL: (2 wickets; 11.4 overs) 142 Fall of wickets: 1-99, 2-138 BOWLING Roach 2-0-33-0-16.50 (1w) Sammy 1-0-14-0-14.00(1w) DR Smith 1-0-9-0-9.00(1w) N Deonarine 2-0-18-0-9.00 NO Miller 3.4-0-56-2-15.27 KA Pollard 2-0-12-0-6.00