Inter Milan went eight points clear at the top of Serie A thanks to Romelu Lukaku's first-half effort away to Bologna.
Lukaku tapped home in the 31st minute after his powerful header was initially kept out by keeper Federico Ravaglia.
Bologna offered little in response, while Inter's Lautaro Martinez struck the post after 50 minutes.
The win means Antonio Conte's take another step towards their first league title since 2009-10.
Elsewhere, title rivals Milan could only rescue a late point against Sampdoria on Saturday.