Six people have been treated for injuries but no one was gored in the sixth running of the bulls at Pamplona's San Fermin festival, officials said.
Navarra Hospital doctor Jon Arizeta said five people sustained contusions and one had a head injury.
Wednesday's run along the 930-yard cobbled-street course to the bullring lasted two minutes, 16 seconds, one of the fastest so far.
Four Americans and a Spaniard have been gored since the runs started on Friday. Most people are injured in falls or by being trampled on by bulls.
In the runs, hundreds of people test their courage and speed by dashing with six fighting bulls.
The nine-day fiesta became world famous with Ernest Hemingway's 1926 novel The Sun Also Rises.