Jannik Sinner's bid to retain his Wimbledon crown nearly came undone at the very first hurdle. The top-ranked Italian had to fight back from two sets to one down to defeat Miomir Kecmanovic 4-6, 6-3, 6-7(6), 6-2, 6-3 in a three-and-a-half-hour first-round battle on Centre Court, as Olympics.com reported.

A nervy afternoon

For long stretches, Kecmanovic — a tenacious Serbian outside the world's top 40 — looked the more dangerous player, taking the opening set and edging a tight third-set tiebreak to move ahead. Sinner, meanwhile, sprayed unforced errors, more than 50 in all, and at one point his all-white kit was marked with blood after a fall left him with a cut on his foot, according to the ATP Tour. It was a far cry from the clinical tennis that has made him the game's dominant force.

Class tells in the end

Once Sinner steadied, though, the gap in quality told. He surged through the fourth set and never trailed in the fifth, closing out the win 6-3 as Kecmanovic's resistance finally faded, Yahoo Sports reported. The scoreline captured a pattern familiar at Grand Slams: a heavily favored champion given an early fright, then a reminder of why he is favored at all.

What it means

The result keeps Sinner's title defense alive but offers a note of caution at the start of the grass-court major. As one of the two men — alongside Carlos Alcaraz — who have come to define the current era of men's tennis, Sinner will be expected to go deep at the All England Club, and a sluggish, scrappy opener is not the springboard he would have wanted. He next faces Portugal's Nuno Borges in the second round, on a surface where his serve and crisp ball-striking usually make for far more comfortable afternoons. The champion is through — but he has been warned.