Muhammad Azharullah claimed four wickets as Northants made a strong start to their County Championship Division Two clash with Worcestershire.
But David Ripley’s men struggled to build on their early heroics as the away side fought back well at the County Ground.
Azharullah took four quick wickets after Worcestershire won the toss and elected to bat.
And the visitors had slipped to 54 for five when Ben Sanderson dismissed Tom Fell for 37.
But Ben Cox (74) and Ross Whiteley (66) helped Worcestershire rebuild and Joe Leach added a valuable unbeaten 51 to take his team up to 277.
Northants then had to negotiate a tricky spell, with Leach taking three wickets as captain Ben Duckett, Rob Keogh and Rob Newton all went cheaply.
Adam Rossington remained unbeaten on 30 and Richard Levi is 11 not out heading into day two, with Northants 64 for three, still 213 runs behind.