Sophie McKinna equalled her own county record on a day of outstanding performances at the Norfolk Athletics Championship at Lynnsport, in King's Lynn.

The 20-year-old from Great Yarmouth threw the shot put out to 15 metres and 74 centimetres – she is now the second ranked thrower in the UK and the top under-23 performer, which will do her hopes of international selection no harm at all.

McKinna's presence showed how important the county event is – as well as proving an inspiration to younger athletes.

Callum Brown set a championship hammer record with a fine throw of 65.61m, a performance that ranks him sixth in the UK this year.

Running the under 20 age group, Dominic Burnham (Yarmouth) sprinted to an excellent 200m time of 21.7 seconds. Elliott Holland followed on from his county 400m record last week with another dominant run.

It was the throwers who continued to produce outstanding performances. Oliver Massingham threw a championship record of 47.09m in the under 17 discus as well as producing a fine shot put. In the same age group, Wesley Matsuka Williams long-jumped 6.54m for a record – again a performance that stands up well in national terms.

Elspeth Jamieson, the English Schools javelin champion, threw a distance of 39.94m while Megan Rushmore, of the West Norfolk club, threw the hammer out to 43.06m in the under 20 age group.

Emily Mace (City of Norwich) recorded a sprint double in the under 17 age group and Harry Houghton (Gresham) also doubled in the under 17 400m and 800m.

In the younger age groups, Katie Goldsmith won a close under 15 800m and Femke Rosbergen dominated the under 13 800m with a good solo run.

Jack White set an under 15 3,000m record of 9:22.3, running from the front. Tayla Benson (West Norfolk) set a 100m hurdles under 20 record of 14.9. There were encouraging numbers of young athletes taking part in the championship, although more senior participation would be welcomed. There will be a second round of county championships at Sportspark in Norwich on June 7.