The top quark pair production cross-section sigma_tt-bar has been
measured in p anti-p collisions at center of mass energies of 1.96 TeV using
Tevatron Run 2 data.  In the beginning of Run 2 both CDF and D0 sigma_tt-bar
measurements in the dilepton channel tt-bar --> WbWb-bar --> ell nu_ell b ell'
nu-bar_ell' b-bar and in the lepton plus jets channel tt-bar --> qq-bar' b
ell nu-bar_ell b-bar + ell-bar nu_ell b q q-bar' b-bar agree with the NLO
(Next-to-Leading-Order) theoretical predictions.  The presence of a top
signal in Tevatron data has been reestablished.