But the 35-year-old went down fighting against WBO European lightweight champion Liam Walsh at Wembley Arena.
The judges were unanimous in their verdict but the margin of the scoring was an insult to Harrison.
They scored it 98-92 and 97-93, twice, in favour of the defending champion but at halfway in the ten -round contest I had it even.
Walsh edged it in the closing segment but Harrison ran him close with a courageous performance full of spirit and determination.
Harrison made the perfect start when he opened up a cut above Walsh’s right eye in the first round. It was unclear whether it had been caused by a big right hook or a clash of heads, but either way the damage was done.
The challenger continued to press forward aggressively and German referee Frank Maass warned him several times for fighting on the break, although both men were guilty.
Somewhat surprisingly Walsh allowed himself to be drawn into trading blows and Harrison made him pay in the fourth with a right to the head quickly followed by a left, both punches rocking the champion.
Like a Big Game hunter stalking his prey, Harrison went in pursuit of Walsh and opened up again briefly in the sixth. But he also looked to be feeling the pace.
Walsh, who had come to the ring with a perfect record of 13 wins,, was no match for his opponent in terms of experience but age and stamina were deciding factors in the end.
The bout was Harrison’s first for eight months and only his third in seven-and-a-half years since the last of his world title contests, in November 2005, and, regrettably it proved a bridge too far. Harrison had fought only twice in the intervening period, comfortably beating Hungarian teenager Gyorgy Mizsei and Englishman Joe Elfidh last year. Neither bout proved a great deal given the quality of the opposition, other than Harrison had not lost his focus and grim determination. But not even the remarkable Muhammad Ali had attempted to bridge such a time span in his three different spells as world heavyweight champion.
So, for Harrison to attempt to upstage The Greatest in a direct head-to-head with Father Time seemed almost preposterous, especially given his fragmented career in the wake of a turbulent lifestyle that dragged him down to the depths of despair when he was locked up in a Spanish prison.
But the Scot gave it his best shot in his quest to put the building blocks in place to regain a world title which, he says, would constitute the greatest achievement of his life and he deserves great credit for that.