The driver of a vehicle within an intersection intending to turn to the left shall yield the right-of-way to any vehicle approaching from the opposite direction which is within the intersection or so close thereto as to constitute an immediate hazard, but said driver, having so yielded and having given a signal when and as required by this chapter, may make such left turn and the drivers of all other vehicles approaching the intersection from said opposite direction shall yield the right- of-way to the vehicles making the left turn.