Alastair Cook admitted he was relieved England were able to overcome the early loss of Andrew Strauss to take command of the opening Test against South Africa at the Oval.
Cook and number three Jonathan Trott put on 150 for the second wicket and the Essex opener paid tribute to his team-mate, who played well in difficult circumstances.
And it scoring 114 not out, Cook finally reached the landmark of 20 Test centuries - almost after after registering number 19.
"It was important to get a good start and I thought Jonathan Trott (who made 71) played exceptionally well after losing Straussy early doors to put on a good partnership," he told Sky Sports 1.
"It was a slow wicket and you had to work hard for your runs. To lose three wickets on the opening day is a good effort.
"Any hundred is important - especially to go from 19 to 20. There were a couple of 94s along the way, which has been slightly frustrating, and it's also a big series as well so to start well was important."
Only the great Sachin Tendulkar has reached 20 Test hundreds at a younger age than 27-year-old Cook, but England's vice-captain is not getting carried away with the statistic.
"I'm not sure I deserve to be in that company but it's nice. I've been getting scores in the Tests versus the West Indies - 20s and 30s. It's nice to go on today and have a good day for England."
South Africa bowling coach Allan Donald gave due credit to Cook, but insisted too that his own charges had done themselves justice.
"Take nothing away from England today," he said. "They batted really well; I really thought that Alastair Cook showed immense discipline and concentration.
"He made us come to him at times. It's a hard day's Test cricket. But I really thought we stuck to our task really well."
Donald had only minor qualms about South Africa's toils.
"There were times I thought we could have been a little bit more aggressive. The only thing that really lacked was the moment where we could pounce, but overall I would take that day.
"We never allowed England to run away with the day. We talked long and hard about how we wanted to 'suffocate' the two left-handers in the crease. I thought we bowled better and better, and the confidence grew.
"We've got to make inroads tomorrow early. That's our big goal, to open up an end and carry on from there. It's a huge day for us tomorrow."