Jonathan Rea must wait until next year to achieve his 100th career World Superbike race win after crashing in the final event of the 2020 season.
Rea, who secured his sixth title on Saturday, was dicing for second with Toprak Razgatlioglu at Estoril when he came off his Kawasaki on lap eight.
Sunday's race two was won by Welshman Chaz Davies on his final race on board the Aruba Ducati after seven years.
Razgatlioglu took victory in Saturday's race one and Sunday's superpole sprint.
Rea had finished fourth in Saturday's race one and fifth in the superpole 10-lapper at the Portuguese circuit after having to start from 15th on the grid following a crash in final qualifying.
The 33-year-old was able to remount his bike and recovered to pick up two points from finishing 14th in the last race of the weekend.
The Northern Irishman already had the hard work done, however, and ran out a comfortable winner of the championship with 11 wins from the 24 races staged.
Having started from pole position, Yamaha-mounted Razgatlioglu immediately took up his familiar position at the head of the field in Sunday's feature event.
He was overtaken by Davies who pulled away to enjoy a winning margin of two seconds over runner-up Scott Redding at the chequered flag, with Razgatlioglu having to settle for third.
American Garrett Gerloff was another faller while battling near the head of affairs while Rea's team-mate Alex Lowes also came to grief.
Despite both Kawasaki runners' misfortune, the Japanese marque secured the manufacturers' championship for a sixth successive year.
"I gambled with a soft front tyre and had a great pace at the beginning of the race. I felt I had nothing to lose by trying that," said Rea.
"I felt really good and at that point in the race I had a better pace than Toprak. When the gap opened in Turn 3 I put my bike there but there wasn't enough space - he closed the door and I tucked the front.
"When I got up my bar was pretty bent and the lever was damaged but I just wanted to finish the last race of the season. I knew I wasn't going to score big points.
"I'm glad we retained the Manufacturers' Championship as it has been a big team effort all season.
"I'm ready to sign off and enjoy these next few weeks before turning our attention to 2021."
Dutchman Michael van der Mark was fourth on his final outing for Pata Yamaha, with Alvaro Bautista and Michael Ruben Rinaldi completing the top six.
|Final World Superbike Championship standings|
|Jonathan Rea (GB)||Kawasaki||360|
|Scott Redding (GB)||Ducati||305|
|Chaz Davies (GB)||Ducati||273|
|Toprak Razgatlioglu (Tur)||Yamaha||228|
|Michael van der Mark (Ned)||Yamaha||223|
|Alex Lowes (GB)||Kawasaki||189|