David Saker, the bowling coach, said England were not attempting to cynically slow the course of the fifth Ashes Test but instead fighting a losing battle against a damp ball.

With Australia's batsmen going well on the second evening, England managed just 11.5 overs in an hour and four minutes - a poor rate that left some fans in the Kia Oval audibly restless.

Field changes and lengthy tactical chats appeared to contribute to the excruciating pace of proceedings, but Saker claimed that surface water from a morning downpour was affecting the state of the ball.

"When the ball got wet it limited who we could throw it to and it limited what we could do with it, which was quite tough," said Saker.

"The main issue was the ball was very wet. We couldn't deliver the ball until it was dry. It was extremely wet out there and that was the main crux of it."

Saker accepted it was a regrettable state of affairs, but pointedly suggested "educated" onlookers would have appreciated England's problem.

"It was [slow], but if the ball is wet there's only one team who can win and that is the batting team. When the bowler has a ball that is wet he can't deliver anything like what he wants to. All you can do is dry the ball. Most of the educated crowd would have known that and some of them wouldn't. It wasn't wet enough to come off but they should be changing the ball in those situations."

The issue provided something of a sideshow to what was another decent day for Australia. Steve Smith celebrated his maiden Test century, making 138 not out as Australia declared on 492 for nine. England openers Alastair Cook and Joe Root then reached 32 without loss in the final hour to frustrate the tourists.

Smith conceded he was under pressure to perform before going on to make his century. A number of Australia's players had been warned their places in the side were not nailed down, with the use of 17 players throughout the series proving such a point.

He reached three figures by smashing a six off the bowling of Jonathan Trott, who had been given the ball despite the fact his side boasted a five-strong bowling attack. To bring up his maiden century in such a fashion will make it all the more memorable for Smith, who revealed afterwards he has already planned to target Trott before delivering the stylish six.

"I probably wouldn't have played quite the same shot if it was someone else bowling," he said. "Jonathan Trott is obviously a part-timer who doesn't bowl too often and I said to Hadds [Brad Haddin] between overs about hitting him over his head and he just told me to keep a clear mind and if it is there go for it. It was there and I managed to get it away."

Smith's best before Thursday's unbeaten 138 was 92 in Mohali earlier this year. He also struck 89 in the drawn Ashes Test at Old Trafford before being caught off the bowling of Graeme Swann.

It would seem the best England can realistically hope for is a draw at this stage, but Saker suggested that victory - and a historic 4-0 success - is still a live option.

"We still believe we can win the match where we sit. We're going to go out and try to put on a big score . . . Both captains want a win. It could easily be a result. What's been really good for me in this series is that when crucial parts of games have come up we've been the better team. That's happened in nearly every Test."