Canadian Felix Auger-Aliassime drops semifinal against John Isner

Felix Auger-Aliassime, of Canada, reacts during his semifinal match against John Isner at the Miami Open tennis tournament, Friday, March 29, 2019, in Miami Gardens, Fla. (AP Photo/Lynne Sladky)

MIAMI -- Felix Auger-Aliassime's dramatic run at the Miami Open finally has come to an end.

The 18-year-old Montreal native lost 7-6 (3), 7-6 (4) to No. 7 seed and defending champion John Isner of the United States in a semifinal of the ATP Tour Masters 1000 event on Friday.

The youngest semifinalist in the 35-year history of the tournament, Auger-Aliassime was broken while serving for each of the first two sets, allowing the American to rally.

The big-serving Isner is now 9-0 in tiebreaks this tournament.

Auger-Aliassime won two qualifying matches before taking another five in a row to advance to the final four. He recorded just the third and fourth breaks against Isner all tournament, but couldn't put him away.

The loss against Isner marked Auger-Aliassime's first in six career matches versus top-20 players.

Fellow Canadian teen Denis Shapovalov, 19, was scheduled to play the Friday evening semifinal against No. 4 seed Roger Federer of Switzerland.

Auger-Aliassime missed a great chance to win the opening set after notching the first break of the match.

But serving at 5-4, Auger-Aliassime had three double-faults, leading to a tiebreak dominated by Isner.

The six-foot-10 American improved to 8-0 at tiebreaks in the event with the first-set win. For Auger-Aliassime, it was his first loss in four tiebreaks at the Miami tourney.

In the second set when leading 5-3, Auger-Aliassime fought off one break point before missing a swinging volley, putting the American back on serve.

Isner got the first point for a mini-break in the second tiebreak and never trailed.

As usual, Isner's serve was his big weapon. He had 21 aces, 15 more than Auger-Aliassime.

Despite the loss, the 57th-ranked Auger-Aliassime is projected to rise to about 33rd in the rankings next week. He is scheduled to return to action at a clay-court event in Morocco starting April 8.