An ace in tennis is a legal serve that lands in the correct service box and is not touched by the receiver, winning the server the point immediately. There is no rally and no return; the ball simply goes by. The ace is the cleanest way to win a point in tennis and one of the most valued weapons in the sport, because it ends the point before the opponent can do anything about it.
What makes a serve an ace
Two conditions must both be met. First, the serve has to be legal, meaning it lands inside the correct service box without any fault. Second, the receiver must not touch the ball at all, not with the racket, not with the body, and not with clothing. If both are true, the point is over the moment the ball bounces twice or sails past the receiver untouched. Miss either condition and it is not an ace.
Ace vs. service winner
The distinction people get wrong most often is between an ace and a service winner. If the receiver reaches the serve and gets a racket on it but cannot put it back in play, that is a service winner, not an ace. The difference is contact. An ace is completely untouched. Even the faintest graze off the frame turns a would-be ace into a service winner. Both win the point for the server, but the statistic recorded is different, and that matters when comparing how dominant two players’ serves really are.
Placement is usually what separates an ace from a returnable serve. Servers aim for the far corners of the box, out wide to pull the receiver off court, or straight down the “T” where the two service boxes meet. A serve delivered to a spot the receiver cannot reach in time will go untouched no matter how the returner guesses.
Why most aces come on the first serve
Players get two serves. On the first serve, they can swing freely and take risks with pace and placement, aiming for the lines and corners of the service box. That combination of speed and angle is what produces most aces. On the second serve, a miss means a double fault and an automatic lost point, so players usually dial back the pace and add spin for safety. Aces still happen on second serves, but they are rarer for exactly this reason. Understanding how a lost point on serve fits into a game is easier once you know the basics of tennis scoring.
What is not an ace
Several outcomes look like aces but are not. A serve that clips the net cord and still lands in is a let, which is replayed, not scored. A serve the receiver touches is a service winner. And a serve that lands outside the box is a fault, not an ace, no matter how fast it was hit. The ace is specifically the untouched, in-play serve.
Where aces matter most
Aces are most valuable in tight moments. On a break point, an ace erases the danger instantly and can swing the momentum of a game. Big servers rely on aces to hold serve cheaply, saving energy over long matches and keeping the pressure squarely on their opponent. Because the serve is the one shot a player fully controls, with no reaction to an incoming ball, developing an accurate, powerful serve is one of the fastest ways to add free points, and the ace is the purest reward for that skill. Height helps, since a taller server can hit down into the box at a steeper angle, but timing, disguise, and spin let players of any size produce aces.
How aces are tracked
In professional tennis, aces are counted as an official match statistic, alongside double faults, first-serve percentage, and winners. Commentators and fans use ace counts as a quick measure of how dominant a player’s serve has been on a given day. A high ace count usually points to a server who is dictating play and rarely letting the opponent into return rallies, which often correlates with holding serve comfortably and forcing more pressure on the returner’s own service games.
Surface matters too. Fast courts, such as grass, tend to produce more aces because the ball skids through low and quick, giving the receiver less time to react. Slower surfaces like clay give returners an extra fraction of a second, so aces are generally harder to come by. None of that changes the definition, though: on any surface, an ace is still simply a legal serve the receiver never touches. It remains the fastest, cleanest way to end a point in tennis.
Frequently asked questions
Does the receiver have to miss completely for it to be an ace?
Yes. For a serve to count as an ace, the receiver must not make any contact at all. If the ball touches the racket, body, or clothing, even a graze, it is a service winner rather than an ace.
Can you hit an ace on a second serve?
Yes. An ace can come off either the first or second serve. It is less common on the second serve because players usually serve with more control and less pace to avoid a double fault.
Is a serve that hits the net cord and lands in an ace?
No. If the serve clips the net and still lands in the correct box, it is a let and is replayed. See our guide to the let in tennis for how that works.
What is the difference between an ace and a service winner?
An ace is untouched. A service winner is a serve the receiver reaches and touches but cannot return in play. Both win the point for the server, but only the untouched serve is an ace.
