Smith and Amla put South Africa in charge

Smith hit a century in his 100th Test and Amla batted for nine hours and nine minutes to make 183 not out as South Africa reached 403 for two at the close, a lead of 18 runs with eight wickets standing

Smith (131) and Amla put on a record 259 for the second wicket and there was no respite for the bowlers as Jacques Kallis (82 not out) joined Amla in an unbeaten third wicket stand of 143.

"It was surreal," said Smith. "A lot of thoughts and emotions went through my head when I reached the hundred but I still had in the back of my mind there was a job to be done. To have played 100 Tests is a terrific achievement and to be able to reach a milestone like this is the cherry on the top. It feels great."

On a slow, dry pitch, offering some variable bounce and turn for the spinners, Smith and Amla dug in and played risk-free cricket to grind down England's bowling attack. Their partnership was two runs higher than the mark set by Smith and current coach Gary Kirsten at Lord's in 2003.

The pair had to work hard in the first hour against the combination of fast bowler James Anderson and off-spinner Graeme Swann. Smith was stuck on 48 for almost half an hour before working Swann to midwicket for three runs to raise the slowest half-century of his Test career.

It took Smith 160 balls to reach his fifty but he unleashed a flurry of boundaries in the next hour and needed just 41 deliveries to notch his second half-century. He raised his 25th Test century two balls before lunch with a square cut for four off Tim Bresnan.

The South African captain went back into cautious mode after lunch, taking 71 more balls to add 28 runs, including a burst of three fours off successive balls against Stuart Broad, before he was bowled off an inside edge by Bresnan. He had faced 273 deliveries and hit 20 boundaries.

"It was a battle of attrition," said Smith. "Three runs an over has been a steady pace throughout the game. The wicket was a bit slow and taking a lot of turn. For me as a left-hander, Graeme Swann was a tough challenge. It was about being strong in my game plan and working through that."

Smith said a key to his success was the way he left the ball. "They (England) tried to frustrate me and I tried to frustrate them."

It was Smith's seventh century against England and his fifth in England. He took his total of runs in the country to 1214 at an average of 75.87. The tally includes two double hundreds. Only Australia's Don Bradman, who scored 2674 runs in England at 102.84, has a better average among visiting batsmen who have played in ten or more innings.

"I feel comfortable in England," he said. "In general you get good preparation time and spend some good time together as a team. It's always a big tour, there's a big build-up and the grounds are great. I've just enjoyed touring here. I think it brings the best out of me.'

Smith will leave the tour immediately after the end of the match on Monday to be with his wife, Irish singer Morgan Deane, who is due to give birth to the couple's first child in Cape Town on Tuesday. He will be back in time for the second Test, which starts in Leeds on August 2.

Amla, meanwhile, reached his 15th Test century off 199 balls with 13 fours. Batting with imperturbable calm, he was content to pick off the loose deliveries with sweetly timed drives and wristy flicks to the on side. By the close he had faced 369 balls and hitting 22 fours.

Kallis, with a relatively poor record in England, took advantage of the solid foundation laid by Smith and Amla as he moved smoothly to a half-century off 94 balls. By the close he had faced 161 balls and hit ten fours.