Bennett made a promising start to his career as a left arm orthodox spin bowler by making a successful foray into Sydney Grade Cricket for St. George in 1973–74 and was selected for the New South Wales combined schoolboy team. During the 1976–77 season, he broke into the New South Wales Colts, the state youth team. Playing in two matches for the summer, he took nine wickets at 10.44. In the second of these matches he scored 102 not out and took a total of 6/34 in an innings win over Queensland Colts. Despite this, he failed to gain selection in the youth team in the following season and he did not reappear until the 1978–79 season. He took six wickets at 12.66 but failed to make any impact with the bat, scoring 19 runs at 4.75. The following season, he played another two games for the Colts, taking five wickets at 28.80 and scoring an unbeaten 116 in one match.

However, the bespectacled Bennett was unable to break through to first-class level until his Sheffield Shield debut in the 1982-83 season at the age of 26. In his debut match against Western Australia, he took 2/74 from 52 overs including 25 maidens, his victims being for Test players Craig Serjeant and Tony Mann. He also scored an unbeaten 30 in a high-scoring draw. In the following match against Tasmania, he took 4/55 from 40.1 overs in another economical performance that featured 22 maidens, but was unable to prevent a seven-wicket defeat. Bennett went wicketless in the next match against South Australia, but did score an unbeaten 59, his maiden-first-class fifty. The spinner broke through for his first five-wicket haul in the next match against Western Australia. After taking 3/47 in the first innings, he claimed 5/39 to dismiss the Western Australians for 197. Of his match total of 65.2 overs, 39 were maidens.

This left New South Wales with a target of 230 and Bennett made 21 not out to see them to the victory with four wickets in hand. Bennett continued his strong debut season in the next match against England, taking 4/65 and 5/123. In the first innings, he denied Geoff Cook his century, having him caught by fellow spinner Holland for 99, and in the second innings he removed Cook again this time for 77, as well as top-scorer Chris Tavare for 147. He made 29 in the lower-order in the run-chase, but was unable to prevent a 26-run defeat. Despite this, Bennett had taken 23 wickets at 21.08 in his first five matches at senior level.

Bennett had less success in the second half of the season, only taking 15 wickets in the remaining eight matches, with a best of 4/9 against Victoria, totalling 6/106 for the match. His victims included Dav Whatmore and Dean Jones, removing both twice. New South Wales made the Shield final and Bennett was retained in spite of his modest late-season form. He contributed little in a narrow victory. His state batted first and contributed only in a total of 271. Bennett bowled economically, but was unable to take a wicket, conceding 50 runs from 29 overs as the Western Australians replied. In the second innings he managed only nine as New South Wales reached 280 to set a target of 293. Bennett was against wicketless, conceding 39 runs from 22 overs, but his colleagues were able to deliver with the ball and New South Wales won by 54 runs.

Bennett ended his debut season with 38 wickets at 28.26 and 356 runs at 32.36. He played in three one-dayers for his state taking three wickets at 30.03 at an economy rate of 3.03.

Bennett was rewarded with selection in a Young Australia team for a month-long tour of Zimbabwe. The squad played two first-class and two one-day matches against the hosts' national team. In the opening first-class fixture, Bennett scored 24 and totalled 2/49 as the tourists won by an innings. He then scored 21 and 35 in the Australians' 126 and 216 as the hosts squared the series; Holland took a total of 3/64. Bennett was not effec