Guildford left out Americans Derek Thompkins and Tyrone Shoulders to bring their line-up under the domestic salary cap and then lost Byrd after 11 minutes. The England and GB international said: 'I went for a steal off Colin (Irish), got to the ball first but then hit his hand.'
After the game, X-rays revealed a fracture to the back of the left hand, but the right-handed Byrd is confident he will return within two weeks.
After Guildford had recovered from a 14-point first-half deficit to lead 58-57, it was Irish who took the game away for Worthing. With Guildford again threatening to regain control, his three-point play took the Bears to a 64-58 lead and safety.
Worthing and Thames Valley Tigers now hold the First Division's only unbeaten records. Manchester Giants, who signed former England international Leo Rogers from Second Division Brixton last week, moved up to fourth position by beating Oldham Celtics 87-61. Derby Bucks scored 32 out of 35 free throws in their 95-77 win over Sunderland Saints, while American Kevin Ellis scored 24 points on his debut for Birmingham Bullets in their 95-75 win at Cheshire Jets. London Towers still wait for work permit clearance on their 6ft 9in US import John Leone, but hardly missed him as 33 points from Peter Scantlebury led their all-English line-up to a 104-85 home win against Hemel Hempstead.