MELBOURNE, Australia—With another Australian Open semifinal spot secured after a four-hour, five-set victory, Rafael Nadal looked toward his support team in Rod Laver Arena and nodded his head. It was like he was just confirming the plan: Five wins down, two to go in his bid for a men’s record 21st major title. On the other side of the net, 14th-seeded Denis Shapovalov broke his racket on the hard blue court after a frustrating 6–3, 6–4, 4–6, 3–6, 6–3 loss to Nadal, who later acknowledged he felt “destroyed” physically on a hot Tuesday afternoon. There were plenty of momentum-shifting moments, including Nadal needing attention for a stomach ailment in the third and fourth sets after dominating the first two. Shapovalov openly complained to chair umpire Carlos Bernardes during the quarterfinal match about Nadal getting longer breaks than players usually are entitled to, and taking too long between points. He took …