Vegeta was fighting Frieza on his own, trying to avenge his fallen race and his father king Vegeta but it turns out Frieza has achieved a form beyond golden Frieza called "black Frieza" and has been able to defeat Vegeta with ease Goku tries saving Vegeta but immediately gets defeated as well but you show up to save both of them

Vegeta: groans in pain

Goku: ngh...Glad the guy came here to stop Frieza...