Opponent marks and lifts my ball on the green thinking it's theirs

No penalty. If your opponent marks and lifts your ball on the putting green because they genuinely think it's their own ball, there's no penalty under Rule 9.5b Exception 2. You simply replace your ball on its original spot (or estimate it) and play on.

What happens next

Your ball must be replaced on its original spot. If the exact spot isn't known, you estimate it as best you can — that's Rule 14.2. You don't drop it; you place it. Once it's back, you play from there with no penalty strokes added to anyone's score.

When the exception applies

Exception 2 to Rule 9.5b covers this exact situation: the opponent marks the spot of your ball and lifts it on the putting green in the mistaken belief that it's their own ball. The key elements are that it happens on the putting green, they mark it first, and the mistake is genuine. If all three are true, no penalty.

What if they didn't mark it or it wasn't on the green?

If your opponent lifts your ball without marking it first, or does it anywhere other than the putting green, the exception doesn't apply. They'd get one penalty stroke under Rule 9.5b, and you'd still replace your ball. The same goes if they deliberately touch or move your ball — penalty stroke, unless another exception fits.

Exceptions that change the answer

• Opponent marks and lifts your ball on the putting green, genuinely believing it's their own ball → No penalty. Replace your ball on its original spot (estimated if necessary) and play on.
• Opponent concedes your next stroke, the hole, or the match → No penalty for lifting your ball (Exception 1).
• Opponent lifts your ball at your request → No penalty (Exception 1).
• Opponent accidentally moves your ball while taking actions covered by Rule 9.4b Exceptions 2–5 → No penalty (Exception 3).

Frequently asked questions

What if my opponent lifts my ball on the green but doesn't mark it first?

They get one penalty stroke under Rule 9.5b. You still replace your ball on its original spot (estimated if needed). The no-penalty exception only applies when they mark it first.

What if this happens in the fairway or rough, not on the green?

The Exception 2 no-penalty rule only applies on the putting green. Anywhere else, your opponent gets one penalty stroke for lifting or moving your ball at rest, and you replace it.

Do I have to replace the ball exactly where it was?

You replace it on its original spot. If that spot isn't known, you estimate it to the best of your ability — that's what Rule 14.2 requires. Don't drop it; place it.

What if my opponent plays my ball thinking it's theirs?

That's a wrong ball situation under Rule 6.3c(1), not Rule 9.5. They get the general penalty (loss of hole in match play), and you replace your ball on its original spot.

Can I claim the hole if they lift my ball by mistake?

No. The mistake is covered by Exception 2 — no penalty, just replace and play on. You only win the hole if they play your ball as a wrong ball (Rule 6.3c) or commit a breach that carries loss of hole.