Victory extended the London 2012 Olympic champion's perfect pro record to 21 wins from as many bouts
Joshua goes the distance before beating Parker in world heavyweight clash
Anthony Joshua was taken the distance for the first time in his professional career before winning a unanimous points decision in his world heavyweight title unification fight with Joseph Parker in Cardiff on Saturday.
After 12 rounds, Britain's Joshua triumphed 118-110, 118-110, 119-109 on the three judges' scorecards.
Victory extended the London 2012 Olympic champion's perfect pro record to 21 wins from as many bouts but was the first in which he'd failed to do so by a knockout.
It also saw International Boxing Federation and World Boxing Association champion Joshua add Parker's World Boxing Organisation belt to his collection.
This result was New Zealand boxer Parker's first defeat in his 25-fight pro career.
Saturday's contest in front of a 78,000 capacity crowd at the Principality Stadium was the first time two previously undefeated heavyweight champions had met for a world title in Britain.
Joshua's win should move him closer to a bout against Deontay Wilder, the American who holds the World Boxing Council's version of the heavyweight title.
Wilder had been due at ringside but did not show and a confident Joshua, speaking to Sky Sports, after his win was confirmed: "Wilder, let's go baby.
"Bring him here and I'll knock him spark out."
Parker added: "Remember that I am the unified heavyweight champion of the world.
"That is 21 professional fights with six world title fights in it.
"My strategy was to stick behind the jab and that secured me another world title belt."
With Joshua earning a reported £15 million and Parker £7m, this was easily the biggest fight of the beaten boxer's career.
"I lost to the better champion tonight," said Parker. "We will be back again stronger and I'm happy I went the 12 rounds."
Shortly before the bout started, Parker's promoter, David Higgins, came to the press seats at ringside while an undercard bout was taking place to allege Joshua's camp had tried to get his boxer's hand wraps changed in a bid to unsettle his man.
Higgins said a Welsh supervisor, acting at the behest of Joshua's camp tried to get Parker's hand wrap changed before he in turn complained to Robert Smith, the general secretary of the British Boxing Board of Control.
Higgins insisted Parker's hands were being wrapped just the same way as they had been for all the fighter's previous professional fights, with Smith, he said, allowing the binding to stay as it was.
Joshua had weighed in at 17st 4lbs (110.4kgs) on Friday, well down from a career high of 18st 2lbs (115.5) against Carlos Takam last time out, while Parker came in at 16st 12lbs (102.3).
As Parker's mother looked on from ringside, Joshua took charge in the centre of the ring early in the first round.
A cut around Parker's left eye was evident from the third round.
Joshua tagged Parker with a solid left in the fourth and landed again seconds before the bell ended that round.
But Parker made some good connections in the fifth and there was a furious exchange early in the sixth, before Italian referee Giuseppe Quartarone intervened.
Joshua, having been struck late when the referee tried to break up the fight, incurred the wrath of Parker's trainer, Kevin Barry, when he too landed late in the eighth round.
Both boxers were frustrated by the referee's early interventions just when it seemed either one of them might unload with a sequence of punches.
The cut round Parker's left eye worsened and blood emerged from the wound in the tenth round.
But a game Parker kept going and the boos at the end of the contest appeared to be aimed at the referee rather than the boxers.