Esteban Chaves (Orica-GreenEdge) won the sixth stage after attacking his escape companions on the final ascent. David De La Cruz (NetApp-Endura) came in for second and Tom Danielson (Garmin-Sharp) in third.
Behind the break, Sky and Wiggins put in a measured effort on the final climb to gradually whittle down the peloton to just a handful of riders. Wiggins then upped the pace in the final kilometre to ensure that Dennis could not pass. In the end, Wiggins managed to distance Dennis slightly on the line to gain valuable seconds.
Adam Yates (Orica-GreenEdge) had been part of the Wiggins/Dennis group and put in a dig in the dying metres to place fourth on the stage behind the three escapees with Wiggins in fifth.
Wiggins now leads Dennis by 30 seconds overall, with Lawson Craddock (Giant-Shimano) in third at 1-48. Yates is fifth at 2-14.
The 2014 Tour of California concludes on Sunday, with the two remaining stages offering little opportunity for any of Wiggins’s rivals to usurp him at the top of the general classification.
Tour of California 2014, stage six: Santa Clarita to Mountain High, 151.8km
1. Esteban Chaves (Col) Orica-GreenEdge
2. David De La Cruz (Spa) NetApp-Endura at 13 secs
3. Tom Danielson (USA) Garmin-Sharp at 41 secs
4. Adam Yates (GBr) Orica-GreenEdge at 53 secs
5. Bradley Wiggins (GBr) Sky at same time
6. Peter Stetina (USA) BMC Racing at 55 secs
7. Rohan Dennis (Aus) Garmin-Sharp at same time
8. Jack Bobridge (Aus) Belkin at 1-07
9. George Bennett (NZl) Cannondale at 1-15
10. Lawson Craddock (USA) Giant-Shimano at 1-16
Overall classification after stage six
1. Bradley Wiggins (GBr) Sky
2. Rohan Dennis (Aus) Garmin-Sharp at 30 secs
3. Lawson Craddock (USA) Giant-Shimano at 1-48
4. Tiago Machado (Por) NetApp-Endura at 2-02
5. Adam Yates (GBr) Orica-GreenEdge at 2-14
Late attack nets Taylor Phinney the stage victory in Santa Barbara and Bradley WIggins maintains overall lead