Angelelli and co-driver Jan Magnussen started from pole and led a race-high 60 laps, but had to settle for fourth place in the #10 entry. The Italian's ninth-straight top four finish keeps his hopes of defending the championship alive, as he heads into next weekend's nine-hour finale only four points behind Pruett and Diaz and 23 adrift of Bergmeister.
Only those four drivers are still mathematically eligible to win the 2006 crown, although Bergmeister's advantage took a hit when his #76 Krohn Racing Riley-Ford was forced to give up a front row grid slot and start from pit-road due to an engine change after the morning warm-up.
Although he and temporary team-mate Jonsson battled through to ninth, Bergmeister served a stop-go penalty after he hit Guy Cosmo's #19 Playboy/Uniden Ford Crawford and was also hit with an additional 30 seconds penalty for 'avoidable contact and dangerous re-entry'.
Patrick Long escaped injury when he pulled out from his pit-stop with the fuel hose still connected. A blaze ensued which was quickly extinguished.
With several frontrunners hampered, Ryan Dalziel and Alex Figge rounded out the top five in the #89 Pacific Coast Riley-Pontiac, securing the best finish for the machine in seven races.
Christian Fittipaldi took the chequered flag in sixth position overall, but was penalised 30y seconds after the race for 'avoidable contact' with Michael Valiante. This dropped the Cheever Racing pairing of Fittipaldi and Hoover Orsi to twelfth overall, and Valiante and co-driver Rob Finlay moved into sixth position.
Patrick Carpentier ran as high as third overall in his first ride with the CITGO Racing by SAMAX team, before the driver change with Milka Duno. They finished seventh.
Wolf Henzler and Robin Liddell scored their third GT class victory of the season ensuring that they head into next weekend's finale just eight points behind standings leaders Andy Lally and Marc Bunting.