It was the feature match in post-section play in the women's singles at the New Zealand championships in Dunedin.
Edwards (43) has now beaten Smith (48) the four times they have played each other in major tournaments.
However, it was not an easy win because Edwards had to come from behind and did not take the lead until the 16th end.
''Val started with a hiss and a roar. She was playing really well,'' Edwards said.
Smith was drawing more accurately and led 11-1 after nine ends.
''I knew I had to pick up my game,'' Edwards said. Smith had got on to the better hand early and was squeezing Edwards out of the game. She played forehand one way and backhand from the other end.
''When I made the decision to change hands I couldn't get on it because Val kept blocking my bowl,'' Edwards said.
''But once I got hold of the little white ball I had a free run to the jack.''
Edwards started with a driving frenzy and had three drives on the first end.
''I never do that. But Val was just getting them too close and I had to try something,'' she said.
''That's just the way the game goes. You can't be in a mindset to do one thing when the opposition doesn't allow you to.''
Smith never felt she had the game won when she led by 10 shots after nine ends.
''You can never be confident against an opponent like Jo,'' she said.
The game's dynamics changed on the 10th end when Edwards pushed out Smith's shot bowl to get her second point and control of the jack.
''I lost the jack when I was playing nicely to a set length,'' Smith said.
''She lengthened it out and I lost my weight.
''Once she got on to a length and on to the safe hand she felt comfortable and her confidence came back.
''The other side of the rink was unpredictable. You didn't know if the bowl would swing or stay out.''
Edwards was playing like the world champion she is with her accurate draw bowls and took command of the game, scoring nine shots on the next five ends. Edwards was only one point behind when Smith gained her next point on the 15th end to lead 12-10.
Edwards failed with her drive and it was the last time she needed to use the power shot in the game. She gained the lead on the next end with three draw bowls around the jack and added singles on the next three ends to lead 16-12 after 19 ends.
Edwards was playing with pinpoint accuracy at this stage and ended the two-hour battle with a two on the 21st end and three on the 22nd end.
''I was accurate in the second half of the game but in the first half I was all over the place,'' Edwards said.
Edwards' run came to an end in her next game when she was beaten 21-20 by Dale Rayner (Johnsonville) in a cliffhanger. Rayner was beaten by Angela Boyd (Taradale) 21-7 in the next round.
It will be a Canterbury-Wellington final in the women's singles on Saturday, with Tayla Bruce (Burnside) matched against Helen King (Victoria).
In the semifinals, Bruce beat Clare McCaul (Silverstream) 21-11 and King beat Angela Boyd (Taradale) 21-13.
