The last thing Sean Williams needed on Wednesday was to get the flu. It was the day before his Test comeback, if you can call it that given his career had only featured two Tests before this one. Perhaps it's better to say it was the day before his restart, because that's how Williams saw this series.

It was another chance for him to prove himself after years of yo-yoing into and out of the selectors' minds, especially for the longer format. They knew he was talented and tough enough - his performances in limited-overs cricket proved that - but they weren't sure he was level-headed enough, mature enough, or even committed enough to don the whites.

Such was their uncertainty that Williams was not under serious consideration for this series after being left out of the Zimbabwe A side to play South Africa A earlier this month. Despite being summoned to Bulawayo from a training camp in Harare specifically for the second fixture of the A series, Williams was excluded from the XI and told to work on his mindset instead if he wanted to be considered for the Tests. Then, he was left off the squad list anyway. Rumour has it that it was only on captain Graeme Cremer's insistence that Williams was eventually included. Then the flu struck.

So although Williams was coughing heavily, feverish and weak, he owed it to his captain, if no one else, to fight through it on the first day. He was needed just after an hour's play, his team already in a precarious situation. Zimbabwe were 35 for 3 and had been stunned by a barrage of short balls from Neil Wagner, who greeted Williams with his most hostile one. It struck him on the helmet and broke the grille.

Williams had barely had time to recover from that moment when Wagner did it again and hit him again. With the same result. Except that the second time, Williams had played a pull and umpire Paul Reiffel thought his bat, not his helmet, had sent the ball to midwicket. Williams was given out. He did not move. He pointed to his helmet as though to offer an explanation but only saw a raised index finger. As he walked off, Williams continued to look at and gesture to the helmet, blaming it and himself and knowing he had made the wrong impression on the powers that be, though not entirely through his own fault.

If they were uncertain about his desire to play Test cricket before, what happened next would have strengthened that assumption. Williams could not be at the ground the next day. Or for most of the one after that. Racked by chills and injected with antibiotics, Williams' best option was to stay in bed to avoid passing it on to his team-mates, some of whom had already started to show symptoms. Regis Chakabva also could not take the field for New Zealand's innings, although he was diagnosed with tonsillitis, which is not contagious.

Both men were summoned from their sick beds towards the end of day three. Even though both would only be able to bat after five wickets had fallen because of the time spent off the field, at 17 for 4 that was imminent. Not only would they have to bat, they would have to save the team from major embarrassment.

"For a minute short of three-and-a-half hours, Williams repaid his captain's faith in him and he proved to his doubters that he is capable and confident player"

When the fifth wicket fell, Zimbabwe had stabilised and Cremer opted to take one for the team instead of send his ailing team-mates out. He saw the day to the close and, for the second time, he batted for Williams.

That night, Williams' wife Chantelle, who had also had the illness passed on to her, became worse. She almost fainted from the symptoms and even thought she may have had a small fit. With that on his mind, Williams travelled to Queens on Sunday morning. Chantelle, her voice rasping from coughing, her throat hoarse, was there with her sisters. The family had come to rally around their man and their team. And they were not disappointed.

Williams entertained from the get-go, with shots that the rest of the line-up, barring Sikandar Raza's carefree cameo, seemed too hesitant to play. He drove and swept and used his feet. He found gaps in the field and went both through and over it.

The only moments that gave away that he may not have been feeling up to scratch came when he called for water five minutes before lunch because he simply couldn't wait that long and when, in the drinks break in the second session, he went down on all fours in a part-stretch, part-retch with the look of a knackered man plastered across his face. For the rest of his innings, Williams was in complete control.

With Cremer playing the perfect foil at the other end, Williams gave Zimbabwe hope they could make New Zealand bat again. He gave them the belief Makhaya Ntini has been trying to drill into them; the kind of belief that only comes with performance. "What they should realise is that they are better than what they think they are," Ntini said. "They can do anything like any other team. They need to be given the space to understand that they can compete. Zimbabwe is going somewhere."

For a minute short of three-and-a-half hours, Williams was in the space where he understood that. He repaid his captain's faith in him and he proved to his doubters within the administration that he is capable and confident player, a scrapper that they should savour having around and a talent they should not take for granted in a country where the player pool remains shallow. So even though the last thing Williams needed was to get the flu, it will be the first thing he thinks of when he looks back on how he broke through and proved that he belongs.