Boxing: Amir Khan rides out the storm on a night of blood, thunder and brutal honesty

After the knockdowns, the storm and plastic surgeons doing emergency work there were moments of honest reflection in the rings of Sheffield, New York and Buenos Aires on Saturday night.

In Sheffield, Amir Khan survived a heavy knockdown in round four to clear his senses and box with intelligence to a decision after 12 rounds against supposedly safe opponent, Julio Diaz.

Khan and his new trainer Virgil Hunter, who never entered the ring and spoke to Khan from ringside, are still circling each other looking for a working pattern; the reality is that they are working against a natural clock.

Khan fought to plan, moved more but still looked vulnerable against Diaz, a quality operator who is not a dangerous puncher, and perhaps it is time for another permanent move to a different weight. It was obvious that Khan stayed at lightweight too long and perhaps his fights at light-welterweight are over.

"Amir fought a sensible fight," said Hunter, who has been working with Khan now for two fights and is a thinking trainer, not a screamer. "We still have a considerable distance to go and we will get there."

According to Richard Schaefer, the travelling envoy from Golden Boy Promotions, Khan will fight for another world title in December, which will give Hunter a summer of much needed love with the Bolton fighter to help him recover the confidence to go with his abilities. The sensible fight, and the most lucrative, would be against Danny Garcia, who retained his World Boxing Association and World Boxing Council light-welterweight titles in Brooklyn just hours after Khan's win.

Garcia stopped Khan last year but was nearly beaten on Saturday by veteran Zab Judah, a man that Khan easily won against a couple of years ago. The pair both needed the work of an emergency plastic surgeon before appearing at the final press conference with their faces covered in gruesome cuts after their brutal fight. Khan and Garcia would be big business.

There will be no world heavyweight title fight for Audley Harrison after he was dropped and stopped in just 70 seconds by Deontay Wilder in what appears now to be the last of his fights. Wilder won for the 28th time by stoppage or knockout and Harrison suffered a seventh loss in 38 fights.

"It could be the end," mused Harrison after the fight. The truth is that Harrison went down from the very first clean punch, just like he crumpled in the defeats to David Haye and David Price. Wilder issued a challenge to Tyson Fury, which could lead to a small stadium fight in September.

In Buenos Aires there was nothing small about Sergio Martinez's triumphant homecoming in front of nearly 50,000 people at the Estadio Jose Amalfiani. However, the weather was dreadful and Martinez's defence of his WBC middleweight title against Martin Murray was brought forward 90 minutes in an attempt to beat the storm.

Murray dropped Martinez in round eight, cut him in round six and was cruelly denied another legitimate knockdown in round 10 in a performance against tremendous odds. Had the 10th-round knockdown not been ruled a slip, Murray would have left the ring with a draw and not the loser at the harsh end of a unanimous decision that was right, but just too wide.

"Sergio Martinez won fair and square – I didn't do enough," said St Helens fighter Murray to end a night of honesty and decency on both sides of the ropes for British boxers.