If your opponent cannot do anything active, then don't rush the position; instead you should let him sit there, suffer, and beg you for a draw.
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[Event "rated untimed match"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "Unknown"]
[Black "Unknown221"]
[Result "1-0"]
[Annotator "David Hayes"]
[BlackElo "0"]
[FEN "8/8/8/pppk1p2/5p2/PPP1K2P/8/8 w - - 0 1"]
[SetUp "1"]
[TimeControl "0"]
[WhiteElo "0"]
1. Kxf4 b4 2. axb4 ( { White dare not try: } 2. cxb4 a4 3. bxa4 c4 4. Ke3 f4+ 5. Kxf4 c3 6. Ke3 Kc4 7. a5 Kb3 8. a6 c2 9. a7 c1=Q+ { Black wins with a large
material advantage. } ) 2... axb4 3. cxb4 cxb4 4. Kxf5 Kd4 5. h4 Kc3 6. h5 Kxb3 7. h6 Ka2 8. h7 b3 9. h8=Q b2 10. Qa8+ Kb3 11. Qe4 Ka2 12. Qa4+ Kb1 13. Ke4 Kc1 14. Qc4+ Kd2 15. Qb3 Kc1 16. Qc3+ Kb1 17. Kd3 Ka2 18. Qc2 Ka1 19. Qa4+ Kb1 20. Kc3 Kc1 21. Qc2# 1-0