Nasser Hussain said he had to dig deep to score the century that put England in a strong position after the first day of the third Test against South Africa on Thursday.

Hussain, who quit as England captain just over two weeks ago following the drawn first Test, made an unbeaten 108 to help his side recover from 29 for two to reach 296 for three at the close.

"I had to work hard for my runs and to have dug deep to get a hundred I'm really proud of myself," he told reporters.

Hussain, whose position in the side was questioned after he stood down from the captaincy, raised his arms in triumph after reaching his 13th Test century.

"The celebration was a bit of a release after the frustration of the last two weeks," he said. "But I didn't feel like I needed to prove anything. If you look at the stats I am having a good season for Essex, scoring lots of runs.

"I felt nervous in the nineties which is quite unusual for me."

The 35-year-old veteran of 86 Tests still has plenty of input into the team he used to lead.

"It's important for me to contribute as much as possible off the field," he said. "But on the field Michael Vaughan must be seen as captain and I will do my best for the team."

Hussain shared a third-wicket partnership of 189 with Mark Butcher, who was not surprised by his former captain's innings.

"He (Hussain) did brilliantly and you wouldn't expect anything less of him," said Butcher, who made 106.

"He was extremely focused on the job at hand and, like all of us, he was stung by the criticism we got after the Lord's match.

"As soon as the vultures start circling over him, he will produce something good.

"He never doubted his worth to the side, he believed he still had the ability to do it and he showed it today."