The Golden State Warriors' title defence got off to a losing start against the Houston Rockets, while the Boston Celtics went down to the Cleveland Cavaliers and lost Gordon Hayward to a serious injury.

Golden State were beaten 122-121 by Houston, who rallied 34-20 in the fourth quarter of Tuesday's NBA season opener.

NBA Finals MVP Kevin Durant had a chance to win it on the buzzer and he actually hit a shot to give the Warriors a 123-122 lead, but after further review, the ball was still on the Warriors star's fingertips when time ran out giving James Harden and the Rockets victory.

Hayward suffered a horrific leg injury in Boston's 102-99 defeat against LeBron James and the Cavaliers.

James and the Cavs spoiled Kyrie Irving's return to Cleveland on a sombre night at Quicken Loans Arena.

HAYWARD SUFFERS GRUESOME INJURY

Hayward signed a four-year, $127million deal to play with the Celtics this offseason. He was supposed to join forces with Irving and rookie Jayson Tatum, and lead a Boston charge that would remove the Cavaliers from their Eastern Conference throne.

Instead, Hayward got two points, one rebound and less than six minutes on the court. The 27-year-old forward suffered a gruesome fractured left ankle in the first quarter as players turned away in horror.

TWO POINT GUARDS DON'T COST ROCKETS ASSISTS

Chris Paul does not like the term 'ball-dominant' but it is understandable why someone would call him that. Also, it is logical to ask the question how he and James Harden would work together in the same system. Would both be as productive as passers?

The answer through one game is certainly yes as Paul posted 11 assists and Harden had 10. The latter also finished with 27 points and six rebounds.

Paul though may need to figure some things out scoring-wise as he had a tough shooting night going two for nine from the field with a mere four points. 

GREEN NEARLY TALLIES TRIPLE-DOUBLE BUT LEAVES WITH INJURY

Draymond Green was his typical self on Tuesday, scoring nine points on two-of-six shooting and one-of-two from the three-point line. He added 13 assists and 11 rebounds and had the Warriors cruising against the new and improved Rockets.

Green had the Warriors in control until he went down with a left knee strain in the third quarter.

After suffering the injury, he did not return to the game. The Warriors announced the problem but not the severity, nor how long they expect the 27-year-old to be out.

CAVS, AND FANS, GIVE IRVING LESS-THAN-WELCOMING RETURN

Irving was booed when he was introduced as a starter for the Celtics, but what was even more surprising was what the Cavaliers' players did to their former team-mate.

Irving hit the winning three-pointer in the Cavs' game-seven victory over the Warriors in the 2016 NBA Finals, so Cleveland had planned on playing a video tribute for him. But the game started and there was no tribute. Why was there not a tribute? Because reportedly Cleveland's players did not like the idea.

Irving went on to score 22 points on eight-of-17 shooting. He added 10 assists as well.

LEBRON DAZZLES

It would not be a Cavaliers game without James delivering a highlight would it? Here he puts Marcus Smart in the spin-cycle.