On Sunday afternoon, Frances Tiafoe and Francisco Cerúndolo won the biggest titles of their careers.It had figured to be a golden day for American men when Tiafoe was taking control of the Halle Open final in Germany against compatriot Taylor Fritz, just as Tommy Paul went up a set and a break of serve against Argentina’s Cerúndolo at Queen’s, in west London.When both matches were over, Tiafoe was holding his fourth ATP Tour trophy after overwhelming and outplaying Fritz, his good friend, 6-4, 6-4 in front of a raucous crowd in Halle. Paul, though could not get over the line. Cerúndolo, who spent the majority of the match as the better player, while being worse in its most important moments, flipped that script to win 6-7, 6-4, 6-3.Tiafoe’s title capped off quite a week for the 28-year-old, who suffered a heart-breaking loss to Italy’s Matteo Arnaldi at the French Open just shy of three weeks ago. In Halle, he beat more than one top-10 player during one tournament for the first time, taking down three in all — Flavio Cobolli, Félix Auger-Aliassime and Fritz. He saved match points in the quarterfinal against Auger-Aliassime, and the win over French Open finalist Cobolli was an impressive one. Against Fritz, he glided to victory.