World champions Russia, who have won Olympic gold in the team segment of synchronised swimming since the Sydney Games in 2000, scored 98.1 points out of a possible 100 for their technical routine, in which teams of eight swimmers dance a sequence that includes a list of required moves.
These points will be added to Friday's "free" routine, which is made up of moves of the team's own choice, for final scores.
China, who narrowly missed out on silver in the duet segment of the competition, came second with 97 points thanks to a crisply executed entry. Spain, with a dance of intricate legwork set to the fast-moving guitar rhythms of Mexican duo Rodrigo y Gabriela, were third, just 0.8 points behind.
Russia claim fourth Olympic synchro sweep
Home team Britain, making their first Olympic appearance, scored 87.3 points, placing them sixth.
Team GB, who are fielding a full synchronised swimming team for the first-ever time at an Olympic Games, posted a score of 87.30 ahead of tomorrow’s free routine.
After competing in the duets competition already alongside Olivia Federici, Jenna Randall was satisfied with the routine but admitted there is still plenty of room for improvement.
"We thought it was a really strong swim today,” said Randall.
“Obviously in synchro, we're always looking for perfection, so there's always lots of things we can fix.
“So we'll go back now and watch the video and see what we can take on to the free routine tomorrow, to make sure that that's up to a better standard.
"Our team were a little bit worried about the crowd, whether we'd be able to hear the counts at the very beginning to walk on, but it was fine. Everyone really enjoyed it.”
The significant fielding of a full synchronised swimming team has allowed Team GB to improve as a group and develop their routines as a unit – an imperative requirement according to Randall.
"With the group, you've got eight people in the water, you've got to make sure that you're nice and close together and also synchronised,” she said.
“That's a lot more demanding than the duet. The duet is a lot faster routine and has more difficulty in there, so those are the two differences between competing in the duet and the team.
"This Olympics was the first time Great Britain as a team in synchronised swimming has actually qualified. It's fantastic for us to be the first to break that barrier. It's looking very positive for Rio.
"Free is our stronger routine because in free, you can do whatever you like. We've got great choreography, it's very British with the Peter Pan theme, everyone loves swimming it, so it's going to be really, really great."
Only way is up for GB synchro swimmers
Russia win synchro duets gold at Olympics