I (dad) had showdowns with all of my kids on this. Here is the full discipline cycle: Explain – spank – leave for minute(s) – return to comfort – reiterate the standard/then repeat the process as many times as you need to. It is important for children not to win – even when they are small. This can be a heart-wrenching process – but you are doing what is best for your child.
Remember – we do the best we can to discipline our children so that they can rule themselves, not just to control them or have them not embarrass us in front of others (both very bad reasons for discipline). The pattern comes from God – who has perfect reasons to discipline us – whereas as parents we do the best we can (Hebrews 12 is probably the most instructive passage on right discipline – read it!).