Smith was the standout batsman from his side as he contributed 144 runs out of Australia's total of 284, rescuing the visitors from a precarious position at 122-8.
Australia's chances now once again rely on the former captain since they boast a small lead of 34 runs with the loss of three wickets at the close of Saturday's third day.
"I was talking to the press before about great players and how they always stand up when you need them," paceman Pattinson told reporters.
"And I think he's done that in this game. Without him, we would be in a bit of trouble."
Smith has been subject to raucous taunts from the passionately partisan English crowd - a trend which was witnessed during the World Cup as well.
"He's been copping a bit from the crowd, which has amused a lot of people, but to his credit, he just gets on with it," Pattinson added.
"He's someone who lifts the group when he's out there."
Smith's fluent stay at the crease was briefly disturbed when Ben Stokes struck him on the side of the head with a well-directed bouncer.
Despite initial concerns regarding his health, Smith shrugged off the blow and was cleared to continue by the team doctor.
"It was quite a good reaction from him (Smith), wasn't it?," said Pattinson.
"We had a little bit of a chuckle in the dressing-room. He always puts a bit of mayo (exaggerates) on things. He's a fantastic player and he seems to be fine now."
Chris Woakes, Stuart Broad's new-ball partner in the absence of James Anderson, admitted it was a difficult task to dismiss Smith on a placid track.
"He's obviously a world-class player and we've got to find a way to get him out," said Woakes, who made a valuable 37 not out to increase England's first-innings advantage to 90 runs.
"I think on this surface in particular, it's hard to force the issue as a bowler.
"The pace has gone out of the pitch so you almost have to build pressure to make sure the batsman makes a mistake.
"But Steve doesn't make too many mistakes, so we've got to find a way."
Paceman Woakes believed Anderson's injury early in the season upset the team management but the bowlers were adamant at doing the job in the remainder of the match.
"(His absence) is a bit of a blow but at the same time us as a unit have to go out there and try to do the job."