Paraguay were never at full throttle, but they found Wales’s mix of experience and bright young kids a problem.
Wales boss John Toshack saw young pretenders slowly rise to the occasion, appearing not to be overawed by a side rated 33 in the world who have qualified for the last three World Cups.
It took Paraguay until the 14th minute to fashion their first chance, Werder Bremen striker Nelson Valdez hitting a fierce volley that Jones blocked to his right. Then he made two outstanding reflex saves in quick succession, first from Valdez and then with an right handed block from Denis Caniza, to keep Wales on level terms.
Wales opened the second period with much more pace and zip about their play and Koumas set off on a 40-yard run that ended with a right footer inches wide of a post.
Jones kept the South Americans at bay with second half saves from Cesar Ramirez, and Carlos Paredes before substitute keeper Price produced an outstanding save at the feet of substitute Jose Cardozo to earn Wales a deserved share of the spoils.
: Paul Jones (Price 66), Edwards, Ricketts, Gabbidon, James Collins, Nyatanga, Fletcher (Robinson 75), Bellamy (Earnshaw 78), Koumas (Ledley 70), Davies (Crofts 76), Giggs (Cotterill 86).
: Villar, Juan Caceres, Toledo, Caniza, Da Silva, Paredes, Ramirez (Cabanas 77), Barreto, Dos Santos (Riveros 67), Acuna, Haedo Valdez (Cardozo 71).
: D McDonald (Scotland).