The Ducks (27-8, 12-3 Pac-12) picked up the series sweep with the win, Oregon's first road sweep in Pac-12 play since the program was reinstated.
Heineman went 2-for-4 with two RBI and a run scored in the game and finished the three-game series 6-for-13 (.462) with three home runs, three doubles, six RBI, four runs scored and a 1.385 slugging percentage.
Oregon jumped out to a lead in the first inning for the second straight day. After a pair of hits put runners on the corners, Payne scored on a passed ball to put the Ducks on top 1-0. Heineman added a RBI double scoring Healy for a 2-0 lead.
Oregon added a pair of runs in the seventh inning to push the lead to 5-1. Tyler Baumgartner drove in the first run with a sacrifice fly scoring Payne. Pinch hitter Ryan Hambright added a RBI single to put the Ducks on top by four.
Knapp pulled Cal within one run in the bottom of the eighth when he hit a three-run home run to left field off reliever Christian Jones.
That was all the closer Cal (16-19, 5-10 Pac-12) would get thanks to Jimmie Sherfy. Oregon's American closer came in to get the final out of the eighth inning and then got three of the four batters he faced in the ninth for his 11th save.
Jake Reed (4-3) picked up the win for Oregon allowing just one run on five hits in 5.2 innings.
The Ducks return to action on Tuesday when they visit Portland at 3 p.m.