Formula Three debutant Lewis Hamilton has returned home after a second race accident at Brands Hatch on Sunday left him in hospital with bruising and concussion.

The new British Formula Renault champion made a much-hyped maiden appearance in an F3 car during the final two rounds of the season but, after impressing in testing, found that race conditions presented an altogether different proposition. A puncture ended his first race in the latter stages, but it was a clash with Manor Motorsport team-mate Tor Graves in race two that made all the headlines on Monday morning.

Having had to start from the back after failing to post a qualifying time for the race, Hamilton was already making progress through the field when Graves came across a slowing Michael Keohane. Caught by surprise, the former Thai national lost control of his Dallara-Mugen and slammed into the side of Hamilton's similar car, pushing it into the barriers. With little movement in the cockpit, the medical crew was despatched to attend to the injured rookie, taking over half and hour to extract him from the wreck.

Despite initial concerns about his condition - Hamilton was unconscious when removed from the car - it was later reported from Queen Mary Hospital in Sidcup that he had no broken bones or other serious injury, although major bruising, concussion and slight memory loss meant that he was detained overnight for observation.

Having satisfied doctors that there was no long-term damage, Hamilton was finally allowed home Monday lunchtime, but has been told to rest completely for the next week or two.