Scotland's Ricky Burns failed to unify the super-lightweight division as his WBA title was taken by IBF and IBO champion Julius Indongo in Glasgow.
Indongo, unbeaten in 21 fights prior to this unification contest, forced his fellow 34-year-old on to the back foot for much of the fight.
Burns rallied in the fifth and sixth rounds but the tall southpaw emerged a worthy winner on points.
That was reflected in the judges' scoring - 120-108, 118-110, 116-112.
"The better man won on the night, no excuses," said Burns. And no-one could argue.
This was Burns' third fight at the Hydro and 13th at world title level, while Indongo - "on a mission" from Namibia's president Hage Geingob - was fighting overseas for only the second time as a professional.
On his first, in December, he knocked out IBF champion Eduard Troyanovsky in Moscow.
It was clear from early in Saturday's fight that Indongo would try to use his greater height and reach to throw jabs at Burns' head, and he did this to good effect in the opening three minutes.
Burns has started slowly in recent fights before finding his rhythm, and the Namibian began much the livelier, bouncing around the centre of the ring against a hesitant home fighter.
Indeed, he looked to have won the first four rounds by dint of his greater work-rate and accuracy, though Burns was beginning to connect with his right.
With their man having 47 bouts under his belt to Indongo's 21, the home fans may have wondered if the tactic was to use his experience to let his opponent tire himself out.
Rounds five and six signalled an improvement in Burns' form, with his aggression rewarded as Indongo was forced backwards for the first time.
The lead Indongo had built was thanks to the accumulation of cleaner shots rather than anything that badly hurt the Coatbridge fighter in his 17th year as a professional.
And, though Burns was still strong in defence, by the time the ninth round had ended he must have realised he was trailing heavily on the scorecards.
His task in the remaining three rounds had to be to stop Indongo for the first time in his nine-year career.
That looked increasingly unlikely as he struggled to get inside to inflict damage. Too often he was over-stretching to land a meaningful shot, and when he did trouble Indongo his opponent snuffed out the attack with footwork and by holding on.
It leaves Burns' dreams of a further unification bout against Terence Crawford in Las Vegas in tatters, though it would be a surprise if he was considering retiring.
'He was better than we thought' - Burns
Ricky Burns: "He was so so awkward. He was a lot better than we thought he was going to be. He can hit as well.
"I'm going to have all the doubters saying I'm finished - but I'll come again.
"He started the rounds fast and the height and reach advantage meant he was out of my distance."
Julius Indongo: "I feel very proud. My home crowd are watching. It's for the whole of Africa. This is so great.
"I am very proud for opening my doors and now the world can see me."
'Burns was one-dimensional' - analysis
Adam Booth, David Haye's former trainer, on BBC Radio 5 live sports extra:
"It was pretty one-dimensional from Ricky Burns, who was trying to jump in from long distance on a fighter who was bigger, with longer arms and a heavy puncher.
"Indongo was dominant, knew what he was about, kept swinging dangerous bombs and didn't let Burns in at all.
"In the last two rounds, when he had the match won, he still wanted to dominate, and like true champions, wanted to get rid of his challenger.
"He ticks all the right boxes. It is going to take a high-level operator to cope with him. I think Terence Crawford is that kind of guy."