Worcestershire had to work hard for any breakthroughs with the ball on day one of the LV=Insurance County Championship fixture with Durham at the Seat Unique Riverside.
Charlie Morris, Josh Baker and Ben Gibbon picked up one wicket apiece, but New Zealander Rachin Ravindra hit a fine unbeaten 178 in what is scheduled to be his only appearance for Durham.
Ravindra and Durham captain Scott Borthwick took full advantage of an easy paced pitch, which has offered little encouragement to the bowlers.
They put together a second-wicket stand of 230 as their side reached 375-3 from 96 overs, with play ending at 6.50pm after a rain break during the final session.
Worcestershire will be hoping to make quick inroads with a second new ball which will be only 15 overs old when play resumes tomorrow.
Their attack stuck gamely to their task on a tough day of first class cricket.
It was a proud day for opener Taylor Cornall, who made his first senior debut for Worcestershire in one of three changes from the win over Leicestershire in the previous Championship match three weeks ago.
Cornall had earlier in the week signed a contract extension with Worcestershire until the end of the 2023 season.
Gibbon, who had impressed when taking five wickets playing for the County Select X1 against New Zealand at Chelmsford, and keeper-batter Gareth Roderick also came into the side.
Borthwick opted to bat on a green-tinged pitch after winning the toss on a cloudy morning.
Morris was rewarded for an over in which he asked questions of Michael Jones when the opener on 21 edged a good length delivery just outside off stump through to Roderick with 32 on the board.
Borthwick was fortunate when an inside edge against Gibbon squirted away to backward square leg for two.
Ravindra, a short-term replacement for Keegan Petersen, who has returned to South Africa early, also edged Gibbon wide of Cornall at second slip for four when on 39 in a moral victory for the bowler.
But false strokes were few and far between, with little beating the bat of Ravindra and Borthwick.
Ravindra completed a 142 ball hundred with his 17th four.
He gave his first chance on 113 when attempting to drive Josh Baker, although it was a sharp opportunity and travelling fast to the left of Ed Barnard at slip.
Baker was rewarded shortly afterwards when Borthwick on 96 went for a sweep and was lbw to end a stand of 230 in 52.1 overs with Ravindra.
Pennington found the inside edge of Ravindra’s bat in the next over, and the ball bounced just past the leg stump.
Baker could have had a second scalp when David Bedingham drove the ball back at a fast pace, and the ball bounced out of his hands and away to the boundary.
It was a difficult chance, but Bedingham did not add to his score before Gibbon dismissed him in the second over after tea.
He played a loose stroke, and Roderick held onto an excellent low catch, diving away to his right at 271-3 to secure a first bowling point.
Durham debutant Jonathan Bushnell then edged Gibbon just short of second slip before he had scored.
The second new ball was taken after 81 overs, and Ravindra and another debutant in Jonathan Bushnell (61 not out) have so far added 104.
Morris ended with 17-2-60-1, Gibbon 18-2-82-1 and Baker 18-3-58-1.