A national record fell and all three British women advanced from their 800m heats on the first night of athletics at Stade de France.

The mixed 4x400m relay quartet of Samuel Reardon (Nigel Stickings, Blackheath & Bromley), Laviai Nielsen (Tony Lester, Enfield & Haringey), Alex Haydock-Wilson (Earl Herbert, Windsor Slough Eton & Hounslow) and Nicole Yeargin (Vince Anderson, Pitreavie) got their Olympic campaign underway in impressive fashion.

After strong legs from Reardon and Nielsen, Haydock-Wilson split 44.70 to hand the baton to Yeargin with GB in first place.

Yeargin kept the Netherlands and Italy at bay, clocking 50.51 herself to guide the team across the line first in a British record time of 3:10.61.

That lowered the national record of 3:11.06 set in winning silver at the 2023 World Athletics Championships in Budapest and laid down a marker ahead of tomorrow’s final, for which only one line-up change is permitted.

Haydock-Wilson said: “These guys put me exactly where I wanted to be. I really wanted to execute the race.

Everything here is so intentional. Martyn (Rooney, coach) has talked us through every scenario, so we don’t feel under pressure. We are good at this.

“We all have our individual aspirations, but when we come together as a team, we can run free. We are loving it.”

The trio of Team GB entrants in the 800m eased through the heats and into Sunday’s semi-finals, with the medals to be decided on Monday.

In the opening heat, Jemma Reekie (Jon Bigg, Kilbarchan) was prominent in the early stages alongside USA’s Juliette Whittaker, opening up daylight on the back straight and extending clear off the home bend to cross first in 2:00.00 flat.

Reekie said: “It felt good, I’m in good shape. I focused on just staying in control and get it done. I know the semis will be hard, but I’m going to go out and do it again.”

At 17, Phoebe Gill (Deborah Steer, St Albans) is the youngest athlete ever to represent Team GB at the Olympics in the women’s 800m and the youngest in track and field as a whole since Linsey McDonald at Moscow 1980.

Gill was in the third heat and it turned out to be the quickest of the lot with Ethiopia’s Worknesh Mesele leading the field through the first lap in 57.4.

Gill said: “It was very fast, I was getting a bit worried at 600m that I was going to have to run the repechage but I am happy that I found in my legs to qualify in third.

“I’m so used to front running in my races, but against these professionals, you have to be on your game constantly.”

She was challenged by Italy’s Eloisa Coiro down the back straight and Gill needed to run 1:58.83 to take the third automatic qualification spot, a shade outside the time she clocked to claim victory at the UK Athletics Championships.

Keely Hodgkinson (Trevor Painter, Leigh) dominated her heat from the front alongside Nia Akins of USA and looked smooth in taking it in 1:59.31.

Hodgkinson said: “I’m just happy to qualify through because it was a quite a tough heat. I’m just glad to make it through safely. The semis will be fun.”

Meanwhile, Scott Lincoln made his second Olympic appearance in the men’s shot put.

After starting with two fouls, he registered a legal mark of 19.69m at the third attempt.

It wasn’t enough to seal progression to the final, with all athletes throwing 21.35m or further or at least the best 12 performers making the medal contest.

See Olympic results here.