Liam Ansell scored twice as the hockey team survived a late fightback from Canada to record a 3-1 victory going into Tuesday’s group match against Germany.
Danny Kerry’s side currently sit second in a group of six, ith the top four set to advance to the quarter-finals.
GB were confident going into this clash having beaten South Africa in their opening match, and Phil Roper and Sam Ward hit the woodwork in the opening exchanges.
With the score goalless at half-time, Ward set up Ansell for the opener before finding the net himself,
Floris van Son gave Canada hope as he scored late on but Ansell scored his second and Britain’s third with Roper turning provider with fewer than five minutes remaining.
Great Britain haven’t medalled in hockey at an Olympics since Seoul 1988 but there are real hopes this team can end that drought.
Meanwhile, pool wins against Canada and Japan sent Team GB through to the quarter-finals of the rugby 7s and despite fears that funding cuts could endanger the side’s Olympic bid, Britain beat Canada 24-0 and the hosts 34-0, with Fiji’s 28-14 victory over Canada on Monday securing GB’s place in the last eight.
The Brits, who won silver in Rio in 2016, face the Pacific islanders in their final pool game in the early hours of Tuesday.
The 12 teams competing were split into three groups of four, with the top two sides and the two best third-place teams advancing to the knockout stages.